Edit: Figured it out, it doesnt work with other hotkey extensions I was using "Open Tabs Next to Current".

Do you accept pull requests? I needed to decrement/increment page on hotkey press, how it works is regex to get the last number in the URL and then increment/decrement then load it.

off to a good start, not quite ready for prime time yet, however - specifically hotkeys still fire when typing in inputs on slack.com