I've experienced the loss of input when I habitually hit escape to exit input mode and then x to delete text. (Normal on vim, does not carrier over the same with Vimium)

This closes the tab, and on restore, the partial input is lost. Had this hit me more than once on Confluence

Good point. Currently though, if you "z" a page you've closed, it preserves your input. The system isn't perfect, but it prevents any fear of accidental closing.

Can't comment on your browser specifically, just that single key shortcuts which are normal input values is not a good idea. People are used to shortcuts with meta keys proceeding them. It's an established behavior and expectation beyond any one system or tool.

Yeah, it's something we thought about a lot before implementing the current system.

We think apps like Superhuman have brought the idea of single-key shortcuts into the forefront, and we really like how much more memorable they are for most users.

We'll definitely learn from our users' feedback though, and we'll work on a solution with them if they have issues with it :)