It’s true we wouldn’t want to commit to not breaking extensions. But a feature request in the form of an actually-implemented browser extension would carry a huge amount of weight. Especially with more than just the author actually using it.
The other answer is that if you’re willing to build a browser extension maybe you could send us a pull request instead? We intend to eventually open source our code and before we’re ready to do that we’re willing to give people we trust (which includes you two, @kenoubi and @drtall) access to the repo.