Rebuild tree - keep folder tree root

Is there any way I could preserve folder tree root when rebuilding tree (to refresh labels)?

I don't think there is at the moment.

Are these labels involving dates/times that mean they need refreshing, or is it something else causing the need?

Do you need to rebuild the tree (Go REBUILDTREE) or does just refreshing it do the job (Go REFRESH=tree)?

I mark files/folders that were modified within specified amount of time.

Go REFRESH=tree does not help. I mean, it adds labels to recently modified files/folders but does not remove these labels when the files are old enough.