The portable builds are fully portable, the profile directory is inside the browser folder. It does not touch appdata at all.
Notable bugs:
The 32 bit build is built with --disable-sandbox. With the sandbox enabled under Vista, the browser fails to open multiple processes which breaks the browser. The 64 bit build is fine. Considering Mypal68 globally disables the sandbox, I don't think it's that bad. If this really is a big issue then please pr a fix.
Most of the r3dfox customizations options do nothing and I have no idea why. So it's hardcoded to be the default. I'm not sure if I can ever fix this under 115 ESR. I figure it's not really worth bothering as most people would want this for userChrome.css themes anyways.
Changes on top of the previous 115.13.0esr build:
32 bit build passes PGO, and yes it was Rust9x. (I use eRust now)
Discord, Snapchat, and Whatsapp should work stock now.
Site specific useragent overrides are back after being removed in 71. general.useragent.override.(site) works in r3dfox.
More privacy respecting default preferences.
I no longer need to hex edit the output, and yes it was Rust9x.
The code is now release 115.13.0 level.
DisplayConfigWindows was added back. (This mitigated some issue on 10 or something idk)
Haven't tested on XP (OCAPI) nor have I extensively stability tested.
Please let me know what bugs or issues you encounter with it.