This should be optional imho, and if you could make two versions, one with, one without the feature, or encapsulate the related code so that I could comment it out, I'd be happy. I prefer having two icons in my personal menu, one which sets tear as default, one for microb, so that I can decide each time which browser I want to activate, and also keep both open. Memory doesn't seem to be much an issue for my use cases.