During animation transitions it would be great if we could move body parts from point A to point B. You could draw a line from point A to point B and bend and twist it in certain locations in order to create a more natural arching and zigzag motion and/or have the single line animation repeat in a reverse and forward motion to allow stuff such as twisting the torso back and forth in a loop. A circular line that connects both ends that you can bend and twist would be good as well to create looping animations. Some creative individuals could even use this to create walking animations and move characters from location to location, such as from a bathroom to a bed or a chair to a counter top.

Example: character A is penetrating character B from behind, character A then spreads their feet for a more stable position and lifts character B into a carry position.

My main problem is if you could actually parent and un-parent characters between animations, such as a character holding another's hand and then un-parenting from their hand and then re-parenting to their ankle to lift that character's leg.

Fingers might be weird since you might have that character make a fist with their hand, but while also moving their whole arm to the side. So maybe don't have the end point of the animation have a place on the map that it stops at and instead leave it free floating so it can animate along with the rest of the movement. Though I would have the animation end point be on a toggle so you can have it either move freely with the rest of the body movements or lock in place to it's end point so things like feet don't keep moving with the rest of the body's movements while they're standing.

Example: character place's their foot down onto the ground while making a continuous twisting motion and arching their back. The top of the body follows along with the motion and direction of the upper body while the legs remain stationary on the end point of their animation path.