Firstly, thanks so much for packaging all these fantastic tools together. I'd sat down to begin working on some terrain tools based on patches and tesselation + heightmaps, and eventually got a bit stuck. I looked around and found your stuff and I'm pretty happy with what it can do.
Experienced frequent crashes in mature project.
Created new URP project in 2020.2.1f1.
Added newest version of MM2 via package manager, with all assets.
Created new scene.
Added new Map Magic GO via menu options in Hierarchy.
Swapped out Map Magic Demo graphs.
Spend some time working.
Change the resolution of the tiles. Sometimes there is a crash. It's a little hard to pin down to an exact set of issues. However, it happens somewhat frequently.