Beware, MM creates combined shaders when connecting nodes, so combining 3 or 4 non non-heavy nodes can generate a heavy shader (and unfortunately, it's not possible to catch those problems gracefully).
I'm planning features to analyze, predict and fix performance problems, but I'm not sure they will be available this year.
Anyway, if you can provide step by step scenarios that lead crashes, please don't hesitate to contact me on Discord.