I personally have only used Metamask as a extension in my Firefox-browser so far, which is a little bit of a annoyance to me to be honest because my main browser is Brave for at least a year now but there the standard wallet is the integrated Brave Browser wallet as far as i know, so everytime i want to do crypto stuff like connecting to sushiswap or something i have to switch browsers. I have not found the time and motivation to look up how to use Metamask as the standard browser on brave which is pretty lazy from me i know but i guess it would not take to much time to set this up.
I can confirm though that i never had problems with metamask in Firefox.