Good Feedback! I would think a checkbox that enables tab function would be best, how would you feel about a FF Plugin that achieves this? My only concern would be that FF has reserved that particular key and it would require special permissions to map it to your needs.
I think it should just be a toggle on the page: "Hijack keyboard shortcuts? Y/N". Figma, Miro, Google and co do it without asking. It's something we've come to expect with web apps, so a toggle would be a fair middle ground.
