At present, AIs follow the global timebase for envelopes, even when mouse-dragging them together with Media Items that have different timebases.
(Legacy envelopes follow the MI timebase when mouse-dragging, but not when copy/pasting using Ctrl+C/Ctrl+V Actions.)
In this image the MI has timebase = beats, while the global timebase for item/envelopes = time. The original MI and envelope are on the left, and the Ctrl+mouse dragged copies are in the middle.
I suggest that AIs should have per-item timebases, similar to MIs.
Alternatively (or additionally), when copying AIs together with MIs, when "Envelope points move with media items" is ENabled, AIs should follow the MI timebase.