It's probably on a todo list somewhere. The difficulty there, I believe, is that /etc/hosts is commonly parsed by your libc, so firefox will have to reimplemen

It's probably on a todo list somewhere. The difficulty there, I believe, is that /etc/hosts is commonly parsed by your libc, so firefox will have to reimplement /etc/host parsing on top of their libc if it does not expose /etc/host entries in some way (glibc and muslc both don't to my knowledge)