Yeah I've run into this already. In the screenshot for my original solution I highlighted a variable called test. Oops, poor name. Trouble is that this change now causes poor names in tightly localized contexts to bleed through the entire codebase :/
There's two directions to solve this:
a) Automatically detect variables with long lifetimes (measured in lines) to highlight. Perhaps this is a refinement of highlighting for
*globals*
b) A way to attach metadata on a per-function or per-fragment basis. Highlight test in this function but not elsewhere, etc.