Maybe the key is to make it look like the animations are moving backwards, but do it outside of an Anim BP completely.
Instead of: Press X button, casting to character you want to reverse anims, getting the animation time and putting it backwards
it could be something like: Press X button, the character you want to animate backwards is hidden in game, a skeletal mesh is placed within the level. From there, maybe we can animate it within Sequencer and have some more control over the animation reversing? I’d imagine there’d be some trouble getting the new skel mesh to start at the right time, so maybe use some smoke + mirrors to cover up the glitchy part (switch cameras or something?)
IDK. I haven’t messed with this in weeks. If I try this out I’ll post my progress.
Good luck! 