I'm not sure how most people are finding my theme, but a quick reminder to everyone who may install it at some point and then create a frivolous issue on the GitHub page:
If you notice your tabs aren't highlighted when modified, double-check the README. Do not create a GitHub issue for this unless you are absolutely sure it's not a case of PEBCAK — otherwise I'm putting your issue in the hall of shame. I may also add your name to the README as a person to be shunned and avoided for eternity. It depends on how many more issues people create without reading the README. Might be fun.