Nope, browsers cannot mask all the stuff, but can do it good enough.
Exaggerated example of this if you run "mac machine" form win. Here (
https://browserleaks.com/canvas) you will be detected anyway as a win machine. And vice versa
So you need at least use mac emitation via mac and win emitation via win.
And there is a lot of points that can leak but whats more important - does it matter? For work with Facebook current popular anti-detect browsers work pretty good.
Anyway. Possible solution for you, if you seek great hardware+software print, might be to work from a real Mac device via separate users for different accounts.