Document Setup gains alignNewObjectsToPixelGrid. When it is on, every
path or compound path drawn in the document (shape tools, Pen,
Curvature, Pencil, Paintbrush, Blob Brush, grids, flares and add-on
shapes) gets the pixel-aligned property and snaps in the same undo
step. Text, paste, duplicate, Place and import are not affected.
- The Transform panel menu has an Align New Objects to Pixel Grid
item for the active document.
- New Document's Advanced Options has the checkbox; the Mobile and Web
presets turn it on, other presets and older saved presets leave it
off, and file.new, Save Preset and Recent keep it.
- The setting is saved with the document only when it is on.
https://helpx.adobe.com/illustrator/desktop/get-started/learn-the-basics/pixel-preview-mode-for-web-graphics.html
Docs: docs/mcp.md, docs/target-app-parity.md, docs/ui-parity.md.