Is alt-left to go back a bad keyboard shortcut for you? It's what I use.

It's also far less likely to be accidentally typed while trying to fill in a form and fumbling the tab navigation.

Every small feature is used by some subset of users, but if you don't trim your software from time to time then feature creep will eventually make it incoherent. Yes, it involves even small details like this one. I don't think learning another hotkey is a big problem, and anyone using keyboard navigation on the web should generally be at least aware of a ton of existing Vim-like navigation extensions (and even browsers)