diff --git a/crates/aep/src/import/effects.rs b/crates/aep/src/import/effects.rs
index 5a8a60285..38c796293 100644
--- a/crates/aep/src/import/effects.rs
+++ b/crates/aep/src/import/effects.rs
@@ -133,6 +133,8 @@ struct ParamOut<'a> {
     col: &'a mut Collector,
 }
 
+/// Imports one parameter of `fx` into its EffectCraft property: its keyframes, the value in its
+/// record or the `pard` default, with a loss for what cannot be read or mapped.
 fn import_param(fx: &AepEffect<'_, '_>, map: &EffectMap, p: &EffectParam<'_, '_>, cx: &LayerCtx<'_>, shown: &str, out: ParamOut<'_>) {
     let ParamOut { group, refs, col } = out;
     if carries_nothing(p) {
diff --git a/crates/aep/tests/it/import/effects_quickwins.rs b/crates/aep/tests/it/import/effects_quickwins.rs
index 792e08d74..f2b0594b6 100644
--- a/crates/aep/tests/it/import/effects_quickwins.rs
+++ b/crates/aep/tests/it/import/effects_quickwins.rs
@@ -10,6 +10,7 @@ use effectcraft_keyframe::Value;
 
 const ECHO_OPS: &[&str] = &["Add", "Maximum", "Minimum", "Screen", "Composite In Back", "Composite In Front", "Blend"];
 
+/// Echo with the definitions After Effects 2026 wrote and the stored `values`.
 fn echo(values: Vec<(usize, f64)>) -> Fx {
     Fx {
         match_name: "ADBE Echo",
@@ -23,9 +24,11 @@ fn echo(values: Vec<(usize, f64)>) -> Fx {
         ],
         values,
         data: vec![],
+        keys: vec![],
     }
 }
 
+/// HDR Highlight Compression's Amount, set and default.
 #[test]
 fn hdr_highlight_compression_amount() {
     let fx = |values| Fx {
@@ -34,6 +37,7 @@ fn hdr_highlight_compression_amount() {
         defs: vec![slider(K::FloatSlider, "Amount", 100.0, (0.0, 100.0))],
         values,
         data: vec![],
+        keys: vec![],
     };
     // `hdr-01-set-all`: 90; `hdr-00-defaults`: no record, 100.
     for (values, want) in [(vec![(1, 90.0)], 90.0), (vec![], 100.0)] {
@@ -43,6 +47,7 @@ fn hdr_highlight_compression_amount() {
     }
 }
 
+/// Echo's values and operator, set and default.
 #[test]
 fn echo_values_and_operator() {
     // `echo-01-set-all` (without its Decay 20, below) and `echo-09-pop5-6`.
@@ -61,6 +66,7 @@ fn echo_values_and_operator() {
     assert_eq!((num(&g, "numberOfEchoes"), v(&g, "echoOperator")), (1.0, Value::Enum(0)));
 }
 
+/// Echo values beyond EffectCraft's ranges are imported as stored and reported.
 #[test]
 fn echo_values_beyond_effectcrafts_range_are_reported() {
     // `echo-03-max`: 30 000 echoes and Decay 100; EffectCraft's Echo uses at most 255 and 1.
@@ -75,6 +81,25 @@ fn echo_values_beyond_effectcrafts_range_are_reported() {
     near(&g, "decay", 100.0);
 }
 
+/// A keyframed Echo parameter keeps its keys as stored and reports the range loss.
+#[test]
+fn echo_keys_beyond_effectcrafts_range_are_kept_and_reported() {
+    // Number Of Echoes keyed 10 -> 30 000: the second key is beyond EffectCraft's 255.
+    let mut fx = echo(vec![]);
+    fx.keys = vec![(2, vec![(0, 10.0), (1000, 30000.0)])];
+    let (g, r) = run(&fx, "ec.time.echo");
+    let found = losses(&r, LossCategory::Effects, "ADBE Echo");
+    assert_eq!(found.len(), 1, "{found:?}");
+    assert!(found[0].contains("Number Of Echoes") && found[0].contains("30000") && found[0].contains("0 to 255"), "{found:?}");
+    assert!(losses(&r, LossCategory::DamagedData, "ADBE Echo").is_empty());
+    // Both keys arrive with their values.
+    let g = g.expect("still imported");
+    let keys = &g.prop("numberOfEchoes").expect("numberOfEchoes").keys;
+    let values: Vec<Value> = keys.iter().map(|k| k.value.clone()).collect();
+    assert_eq!(values, [Value::Scalar(10.0), Value::Scalar(30000.0)]);
+}
+
+/// Linear Wipe's values, set and default.
 #[test]
 fn linear_wipe_values() {
     let fx = |values| Fx {
@@ -87,6 +112,7 @@ fn linear_wipe_values() {
         ],
         values,
         data: vec![],
+        keys: vec![],
     };
     // `linwipe-01-set-all`.
     let (g, r) = run(&fx(vec![(1, 10.0), (2, 77.0), (3, 16.0)]), "ec.transition.linearwipe");
@@ -99,6 +125,7 @@ fn linear_wipe_values() {
     near(&run(&fx(vec![]), "ec.transition.linearwipe").0.expect("imported"), "angle", 90.0);
 }
 
+/// Offset's Blend With Original as a percentage and its centre as a point.
 #[test]
 fn offset_blend_is_a_fraction_and_the_centre_a_point() {
     let fx = |values| Fx {
@@ -107,6 +134,7 @@ fn offset_blend_is_a_fraction_and_the_centre_a_point() {
         defs: vec![other(K::Point, "Shift Center To", Default::Point(0.5, 0.5)), slider(K::FixedSlider, "Blend With Original", 0.0, (0.0, 1.0))],
         values,
         data: vec![],
+        keys: vec![],
     };
     // `offset-02-chk-toggled`: Blend With Original stored 1.0 is 100 %.
     let (g, r) = run(&fx(vec![(2, 1.0)]), "ec.distort.offset");
@@ -118,6 +146,7 @@ fn offset_blend_is_a_fraction_and_the_centre_a_point() {
     near(&run(&fx(vec![(2, 0.25)]), "ec.distort.offset").0.expect("imported"), "blend", 25.0);
 }
 
+/// Color Stabilizer's points, Sample Size and Stabilize, default and set.
 #[test]
 fn color_stabilizer_points_sample_size_and_stabilize() {
     let fx = |values| Fx {
@@ -132,6 +161,7 @@ fn color_stabilizer_points_sample_size_and_stabilize() {
         ],
         values,
         data: vec![],
+        keys: vec![],
     };
     // `colstab-00-defaults`: Levels, the points at 20 %, 50 % and 80 % of the width.
     let (g, r) = run(&fx(vec![]), "ec.color.colorstabilizer");
diff --git a/crates/aep/tests/it/import/fx_inject.rs b/crates/aep/tests/it/import/fx_inject.rs
index 9687e2d6c..81e6a821a 100644
--- a/crates/aep/tests/it/import/fx_inject.rs
+++ b/crates/aep/tests/it/import/fx_inject.rs
@@ -37,6 +37,7 @@ pub enum Default {
     Color([u8; 4]),
 }
 
+/// The parameter type code `pard` byte 15 holds for `k`.
 fn kind_code(k: ParamKind) -> u8 {
     match k {
         ParamKind::Layer => 0,
@@ -57,10 +58,12 @@ fn kind_code(k: ParamKind) -> u8 {
     }
 }
 
+/// `v` as a big-endian 16.16 fixed-point value.
 fn fixed(v: f64) -> [u8; 4] {
     ((v * 65536.0).round() as i32).to_be_bytes()
 }
 
+/// The 148-byte parameter definition (`pard`) of `d`: type, name, default and range.
 pub fn pard(d: &Def) -> Chunk<'static> {
     let mut b = vec![0u8; 148];
     b[15] = kind_code(d.kind);
@@ -99,6 +102,7 @@ pub fn tdmn(name: &str) -> Chunk<'static> {
     Chunk::data(*b"tdmn", b)
 }
 
+/// A UTF-8 string chunk (`Utf8`).
 fn utf8(s: &str) -> Chunk<'static> {
     Chunk::data(*b"Utf8", s.as_bytes().to_vec())
 }
@@ -126,6 +130,27 @@ fn record(template: &Chunk<'_>, v: f64) -> Chunk<'static> {
     Chunk::list(*b"tdbs", kids)
 }
 
+/// A keyframed value record: `record`'s header with a key list of linear one-component keys.
+fn keyed_record(template: &Chunk<'_>, keys: &[(i32, f64)]) -> Chunk<'static> {
+    let Body::List { children, .. } = record(template, keys.first().map_or(0.0, |k| k.1)).body else { unreachable!("record builds a LIST") };
+    let mut children = children;
+    let mut lhd3 = vec![0u8; 52];
+    lhd3[0..4].copy_from_slice(&0x00d0_0beeu32.to_be_bytes());
+    lhd3[8..12].copy_from_slice(&(keys.len() as u32).to_be_bytes());
+    lhd3[16..20].copy_from_slice(&48u32.to_be_bytes());
+    let mut ldat = Vec::new();
+    for (time, value) in keys {
+        let mut rec = vec![0u8; 48];
+        rec[0..4].copy_from_slice(&time.to_be_bytes());
+        rec[4] = 1;
+        rec[5] = 1;
+        rec[8..16].copy_from_slice(&value.to_be_bytes());
+        ldat.extend(rec);
+    }
+    children.push(Chunk::list(*b"list", vec![Chunk::data(*b"lhd3", lhd3), Chunk::data(*b"ldat", ldat)]));
+    Chunk::list(*b"tdbs", children)
+}
+
 /// An effect instance: its match name, display name, parameter definitions (after the input
 /// layer, before the built-in entry), the 1-D values stored (`parT` index, value) and the
 /// arbitrary data stored (`parT` index, bytes).
@@ -135,12 +160,18 @@ pub struct Fx {
     pub defs: Vec<Def>,
     pub values: Vec<(usize, f64)>,
     pub data: Vec<(usize, Vec<u8>)>,
+    /// Keyframed 1-D parameters (`parT` index, (time units, value) per key), linear keys; the
+    /// parameter then has no entry in `values`.
+    pub keys: Vec<(usize, Vec<(i32, f64)>)>,
 }
 
+/// The match name of parameter `i` of `fx` (`<match>-NNNN`).
 fn param_name(fx: &Fx, i: usize) -> String {
     format!("{}-{i:04}", fx.match_name)
 }
 
+/// The effect's `sspc`: its name, the parameter definitions (`parT`) and the stored values
+/// (`tdgp`), each value record copied from `template`.
 fn sspc(fx: &Fx, template: &Chunk<'_>) -> Chunk<'static> {
     let n = fx.defs.len() + 2;
     let mut part = vec![
@@ -165,6 +196,10 @@ fn sspc(fx: &Fx, template: &Chunk<'_>) -> Chunk<'static> {
             values.push(Chunk::list(*b"aRbs", vec![Chunk::data(*b"aRbp", d.clone())]));
         }
     }
+    for (i, keys) in &fx.keys {
+        values.push(tdmn(&param_name(fx, *i)));
+        values.push(keyed_record(template, keys));
+    }
     Chunk::list(*b"sspc", vec![nested(*b"fnam", vec![utf8(fx.name)]), Chunk::list(*b"parT", part), Chunk::list(*b"tdgp", values)])
 }
 
@@ -194,6 +229,7 @@ fn find_glow_template(chunks: &[Chunk<'_>]) -> Option<Chunk<'static>> {
     None
 }
 
+/// Replaces every Glow (`ADBE Glo2` with its `sspc`) below `chunks` with `fx`; the number replaced.
 fn replace_glow(chunks: &mut [Chunk<'_>], fx: &Fx, template: &Chunk<'_>) -> usize {
     let mut n = 0;
     for ch in chunks {
@@ -239,10 +275,12 @@ pub fn losses(r: &ImportResult, category: LossCategory, match_name: &str) -> Vec
     r.report.losses.iter().filter(|l| l.category == category).flat_map(|l| l.details.clone()).filter(|d| d.contains(&tag)).collect()
 }
 
+/// The value of property `id` of `g` (panics when it is missing).
 pub fn v(g: &PropGroup, id: &str) -> Value {
     g.prop(id).unwrap_or_else(|| panic!("no {id} in {}", g.match_id)).value.clone()
 }
 
+/// The scalar value of property `id` of `g`.
 pub fn num(g: &PropGroup, id: &str) -> f64 {
     match v(g, id) {
         Value::Scalar(x) => x,
@@ -250,11 +288,13 @@ pub fn num(g: &PropGroup, id: &str) -> f64 {
     }
 }
 
+/// Asserts that property `id` of `g` is `want` (relative 1e-6).
 pub fn near(g: &PropGroup, id: &str, want: f64) {
     let got = num(g, id);
     assert!((got - want).abs() <= want.abs().max(1.0) * 1e-6, "{} {id}: {got} != {want}", g.match_id);
 }
 
+/// Asserts that the point property `id` of `g` is `want` (within 0.01).
 pub fn pt(g: &PropGroup, id: &str, want: [f64; 2]) {
     let Value::Vec2(a) = v(g, id) else { panic!("{id}") };
     assert!((a[0] - want[0]).abs() < 1e-2 && (a[1] - want[1]).abs() < 1e-2, "{} {id}: {a:?} != {want:?}", g.match_id);
@@ -265,14 +305,17 @@ pub fn slider(kind: ParamKind, name: &'static str, default: f64, valid: (f64, f6
     Def { kind, name, default: Default::Number(default), valid, items: &[] }
 }
 
+/// A popup definition: default item (1-based) and items.
 pub fn popup(name: &'static str, default: u32, items: &'static [&'static str]) -> Def {
     Def { kind: ParamKind::Popup, name, default: Default::Index(default), valid: (0.0, 0.0), items }
 }
 
+/// A definition of another kind (angle, point, colour, ...) with `default`.
 pub fn other(kind: ParamKind, name: &'static str, default: Default) -> Def {
     Def { kind, name, default, valid: (0.0, 0.0), items: &[] }
 }
 
+/// The definitions written here read back as the reader decodes After Effects' `pard`.
 #[test]
 fn pard_layout_decodes_as_written() {
     // Echo's Decay (float, valid 0..100, default 1), Linear Wipe's Feather (fixed, valid max
@@ -291,6 +334,7 @@ fn pard_layout_decodes_as_written() {
         ],
         values: vec![(1, 20.0)],
         data: vec![],
+        keys: vec![],
     };
     let bytes = bytes_with(&fx);
     let file = parse(&bytes).unwrap();