I happen to be working on this same issue I found some posts on it already.
https://forums.creativecow.net/thread/2/1001438
https://forums.creativecow.net/archivethread/2/788903
The idea is to basically split the layer where you want to unparent it at. You can do it for effects too via instances using a script listed in other topic posts.
If you want a slightly more dynamic way I made an expression that allows you to do this based on setting a specific frame to stop following at via a effect slider. 2479_followunfollow.aep.zip
The idea is that it follows the position(position and rotation in my example) or whatever ever value you set until it gets to the frame you want it to stop at. Then it keeps that value for the rest of the comp. This script only works once but you could create a series of statements to work multiple times or do it with loops I suppose.
I haven’t tested it yet in my actual project yet but I plan to use it or use the split method.
Hope this helps
Greg
followItem=thisComp.layer("Leader").transform.position
followerItem = transform.position
//
FrameVal = effect("Frame Value")("Slider");
TimeStopVal = framesToTime(FrameVal, fps = 1.0 / thisComp.frameDuration)
currentFrame = timeToFrames(t = time + thisComp.displayStartTime, fps = 1.0 / thisComp.frameDuration, isDuration = false);
//
if(currentFrame <=FrameVal ){
followerItem= followItem;
}
else{
followerItem = followItem.valueAtTime(TimeStopVal)
}
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