Thanks so much for this. I confirmed that this works on a virgin firefox install, and was able to get it working on my config after messing with the search settings to enable search suggestions.

The key here is that if firefox sees an exact match to a bookmark keyword, it will put that as the top hit on the address bar. So if you put a short keyword for your bookmark (in this case, ha for the aforementioned hackaday example) you can type in h a {enter} and it will take you to the full url of the bookmark instead of the base.