I actually use thumbnails sort of when I am working on a larger digital oil, something I couldn't really do when painting real oils. I'll pick out a section of the digital oil after laying down a few layers of base colours and blocks of colour and then make a layer that is a drawn thumbnail around the bit I am going to work on. Then I can really go in and work on detail and such. This also makes it easier for me to share bits of my larger oils now that I like to do as I am sharing a piece over a few posts and weeks.
I like how you are trying out these sections like this. I do that somewhat too when trying out environments to set a painting in.
Good job combining family and work time together. It is an art in and of itself.