Looks really good. However, for, say, rail systems or anything that doesn't involve you literally painting the entire base, there is a tendency to have the +1 and +2 options to create a line of, say, hazard concrete over the rails as a border, which only moves if you try to fix it. Maybe an option to only draw tiles in areas you actually selected?

Also, the popup being directly part of selecting the tool is annoying. Suggest that be two seperate options. a menu, and a tool. Plus, the menu has that "Pin" option which doesn't work.