That’d be intrusive, if saving was a background operation, then autosave would be mandatory but it isnt, it interupts what you were doing, so a reminder is better, just click it more often, or reduce/increase how long it takes to remind you in settings

as Mzati said, it might can cut your animating progress and you would be having to wait which can get annoying so only recomending to save might be better since sometimes you dont add anything to the project you would be just playing around