I couldn’t edit/update my last post. After the 08-27-2022 Testing Branch release, Firefox 104 repository/official version has WebGL running like butter again, too. 
UPDATE: I reinstalled Firefox 104 from the repository (was running Flatpak on desktop) and noticed it still hiccuping on my desktop installation (it was fine on our much lower spec’d laptops when tested and originally made this post). I changed gfx.webrender.all to False in about:config and it was just as smooth again 
(Note; this setting was of no avail either way with Firefox 103)