I would really appreciate if you channel upstream:

I often use baobab to see what sucks out my precious SSD space.  Going
through all directories upon each occasion is not very productive.  If I
could simply clieck "save state" and then upon later invocation to
visualize not current disk utilization but difference (e.g. only
"positive" increments in consumption) for directories -- that would be
uterly useful since it would point me right away what has consumed space
since last inspection.

thanks and cheers!