I use different accounts for my work GitHub and my personal GitHub, so this approach would be great if I shared a machine for both of them to keep separation.

I find the premise to be potentially wrong already.

Is a `dotfiles` repo personal? I don't usually push to my own repos from my work machines, but I do want to pull and push config updates while not disclosing my work email there or rewrite commits all the time (it's not secret, I just don't want it there).