Could be tricky when you are in the compose area.... Tab could move between menu items OR insert a tab into your draft note. How would you resolve that? Go into an editing state and escape with ESC?
Discussion
Time to ask the BTC designers we have, maybe? I'd be happy with some hard-coded keys to navigate obvious contexts (like scrolling a feed, j/k-ish), paired with some dynamic focus highlight after a special key, just like the vimium browser extension. I wonder if we have good keyboard interaction designers out there.
Right now you can already use