Basic question of how to switch between trackers for video stabilization

I just started to use Blender for Video editing, it is nice!

Now I have a movie clip I need to stabilize. I learned how to create a marker, create a track based on this marker, and then use this track for stabilization.

It works fine, except that the movie clip is complex. I would need to use 6 different tracks in different phases, and switch between these at different points in time. However, I am uncertain how to do that. If I create more than than marker and add them to “Tracks for localization”, they are used in the whole movie clip even when they fail to track.

How should I best do this?

I find there is something called key frames, is that the tool that can solve this?

Or maybe I am doing it all wrong?

You really just have to have 6 concurrent trackers, not the same 6 all the way thru. Though you do need to pick the best frame range (keyframes) to describe parallax motion, for the solve to be effective.