It might be just me, but I think key bindings should definitely not be easily configurable or even changed across release. They should.be standard, pervasive, and set in stone.
For those who really want configurable key bindings in Firefox I think there are already a couple of extensions that do this for you.
I think this was focused on maintaining code. Replacing C-style arrays with std::array can be a daunting task, depending on how the project is structured.