Yup! I've tried this solution myself but just found it incredibly hacky and un-intuitive. I hope the nicer UX (hotkeys!) allows for a better experience. In the future I hope to plan to have better syncing (cloud, sync into a traditional bookmark for mobile use), x-platform, share w/ others, tighter omnibar integration, etc. But you're right that there are reasonable solutions out there currently, but I hope Shortlink provides a lower barrier to entry and less configurations to fuss over.

As for Firefox, I'm not really a user myself, I've just tried it real quick and it seems like you have to type quite a bit to get the omnibar(?) to prioritize the bookmark result over the other autocompletes, as for shortlink you can type m/[shortlink] and be guaranteed to hop over to the site you saved. Good food for thought though!