“Darken everything except selected area” is the feature I use the most.
However, it is not possible to use it in order to highlight multiple areas as background overlays added for each area multiplies.
Currently it looks like this (feature was applied 4 times)
It seems like solution to the issue is quite simple:
<default amount> + <inverted overlay's darken value>;
Thanks for your note! I’ve added your suggestion to our roadmap list.