This is exactly my experience. Like C++, a Scala project needs a document describing what parts of the languages should not be used, or avoided in most cases.

There is a great danger in this. Hence I prefer a language that is smaller and helps me to avoid cruft being checked in to version control. Linters are a solution, I've seen it work in JS/TS project. Not sure if C++/Scala have linters up to the feature level of JS/TS linters.