(I, toast, wrote the original merge request, but Alam made this merge request because I made a mistake. Twice. In a row.)
Solid objects are now no longer intangible when your z is less than the other object's.
I originally thought the bug was limited to just solid objects on slopes (hence the branch name), and was wondering about undesired side effects - but looking at this gfy, this was a major bug that slopes made easier to expose.