Question How to implement "Hold mode" for Custom track?

I created a timeline track where you can specify tracks for NPCs so they can walk on the destinated path. this is has been a great help for making prototype cutscenes. However, when the timeline stops the transforms for the characters are permanently modified. I then found this thread
https://forum.unity.com/threads/temporary-preview-changes-from-custom-timeline-track.650902/

where it is talked about to reset the values in editor. This solved my problem of my character's positions are set as dirty and getting saved.

however, the same thing happened to my timeline in play mode. the characters' positions reset to the beginning of the timeline after it finishes playing.

How do I implement something like a "HOLD MODE" in activation track so when the timeline finishes playing, it keeps the characters' position?