Neither of those are "crazy shit." It's just complex because the environment offers specific features like automatic GC with async preemption in a compiled language which pretty much requires it.
Complex engineering isn't something to be avoided by default.
Agree, but I think there is a point to be made here: Go as a language has more subtle runtime invariants that must be upheld compared to other languages, and this has led to a relatively large number of really nasty bugs (eg. there have also been several bugs relating to native function calling due to stack space issues and calling convention differences). By "nasty" I mean ones that are really hard to track down if you don't have the resources that a company like CF does.
To me this points to a lack of verification, testing, and most importantly awareness of the invariants that are relied on. If the GC relies on the stack pointer being valid at all times, then the IR needs a way to guarantee that modifications to it are not split into multiple instructions during lowering. It means that there should be explicit testing of each kind of stack layout, and tests that look at the real generated code and step through it instruction by instruction to verify that these invariants are never broken...
Complex engineering isn't something to be avoided by default.