I think it might be useful to define what a non-user visible change is.
Possibly with reference to making releases.
In a sense perhaps a non-user visible change is a 3rd category, like bug-fix or feature.

When I say non-user-visible change I mean one of:

• Refactoring to change internal structure (but not the public API)
• Updating a comment
• renaming a variable
• Fixing a mistake in the tests

Some things sound similar like:

• Performance improvements
• updating documentation.

But are not.

Was reminded of this in
JuliaDiff/ChainRules.jl#296 (comment)