Or just use this and never click anything but refresh:
Weird. I can't even find that in my General settings but it appears to also be in the Dev Tools > Network tab.
How have I never noticed this?! Thank you.
On windows, you have two options: ctrl + f5 and shift + f5 which i couldn't find on macOS.
I personally use Ctrl+Shift+R (or Ctrl+F5, it's the same), but I'd still really like this in Firefox!
Or refresh using the keyboard shortcut CMD + SHIFT + R