IMO creating custom rules is problematic - when projects import external code, rule conflicts become inevitable. C++'s type system might be complex, but at least there's consistency across header files within a project.

Regarding type checkers: while I don't love optimizing code just to make them run faster, most Python patterns can be implemented in statically checkable ways without much compromise. The benefits typically outweigh the costs. Python's dynamic features are powerful but rarely essential for everyday tasks.