Pixel 2 XL, also no issues or even any noticeable deltas between Chromium based browsers and Firefox.
I'm using Fold 5 and can tell a difference in scrolling performance between Samsung Internet and Firefox. There are also some issues regarding how the UI handles transition between folded to unfolded and vice versa.
Pixel 6 here, no issues.
Pixel 2 XL, also no issues or even any noticeable deltas between Chromium based browsers and Firefox.
I'm using Fold 5 and can tell a difference in scrolling performance between Samsung Internet and Firefox. There are also some issues regarding how the UI handles transition between folded to unfolded and vice versa.
This is a known issue
https://bugzilla.mozilla.org/show_bug.cgi?id=1813844
Pixel 6 and Samsung A45 here Firefox is so fast I never had a complain or needed to use chrome or Samsung browser