Can AE nudge a keyframe(s) one frame at a time via keyboard shortcut or menu command?

To nudge a keyframe or keyframes in the Timeline:

1. Select the keyframe or keyframes to be nudged.
2. Then press Option Right Arrow to nudge to to the next frame or press Option Left Arrow to nudge to the previous frame (use Alt if running Windows).

Optional: Add Shift to nudge 10 frames at a time.

If frequently nudging the same keyframes, consider using Keyframe Color Labels (right-click the keyframe or keyframes > Label) to quickly reselect the Color Label Goup later (right-click a keyframe and choose Label > Select Label Group).

-Warren

https://www.linkedin.com/learning/after-effects-guru-mastering-the-timeline-2/how-to-nudge-keyframes

Opt/Alt + arrow (left or right)

The closest I can suggest is if you use Page Down or Page Up to move the current time indicator one frame back or forward, then hold Shift while dragging your keyframe, it should snap to the time indicator.

No, there is no such feature. There's a bunch of scripts on AEScripts.com that deal with moving keyframes around, but that's pretty much it.

Mylenium