arenaodev but as I'm seeing, even while playmode selecting the timeline to any specific point only freezes the animation, it's not playing the animation at that specific timeline point I'm selecting.
Unfortunately placing the cursor in the timeline and having it display the respective animation frame at the skeleton is exactly what is currently not supported (yet), regardless of whether play-mode is entered or not. What I meant by entering play mode and adjust the hitbox size and position is to let the game play your animation in a loop (e.g. by having one animation clip loop in the Mecanim controller), then pause the game and forward frame-wise until you arrive at the respective timepoint, then adjust any hitbox position and scale accordingly. Then framewise-forward to the next critical timepoint, adjust the hitboxes again, and so on.
Sorry that my previous answer was not clear.
arenaodev Is there at least something I could do to set the current animation to the state it should be while I'm selecting a specific time in it's timeline while in playmode? That alone would be more than enough.
One thing that comes to mind is to use the Timeline extension , where you could scrub through an animation clip during play mode and have it apply to your in-game skeleton.
You can check out this video if you are not yet familiar with using this package:VIDEO
