Hey, yes the issue is I think, the animation with a lot of keys have different frame duration. Maybe this could be improved in the future by introducing a time input instead of using the frames.
So yes for the moment. If all the frames have same duration, one key is created at the beginning and one at the end. Else multiple keys can be added if the frames duration differ. (I see there is a lot on the timeline maybe I could improve the amount of keys required)