any support for mirrored loop animation?

i often get animations from mixamo that cover an entire action from start to finish like pulling a rope

i split it into 4 separate animations
pulling a rope pickup
pulling a rope idle
pulling a rope pull
pulling a rope drop
no problem except for the idle animation. i choose a couple of frames between pickup and pull and loop them at slow speed
but at the end of each loop cycle there is a jerky transition back to start
i know i could go into blender and manually make an idle animation that smooth transitions back to start but that's a lot of work
it would be nice if in the importer, where you select the frames and hit loop, that it supported a loop with mirror option.
is there anything like that?
thanks