If you don't care about the extra security and privacy stuff that it adds and just want an unfucked firefox fork you can follow this reddit comment:
/u/aaaaaaaaabbaaaaaaaaa
Go on about:config. Type "privacy.clearonshutdown". Many options will show up. Make sure those between "privacy.clearonshutdown.cache" to "privacy.clearonshutdown.sitesettings" (including the two) are set to FALSE.
Then type webgl.disabled and set it to FALSE.
Go on Settings:
On General->Startup, Enable Open previous windows and tabs
On Privacy & Security->Cookies and Site Data, uncheck "Delete cookies and site data when LibreWolf is closed"
On Privacy & Security->History, check the three options there.
On LibreWolf, disable "Limit cross-origin referrers", "Enable ResistFingerprinting", "Enable letterboxing", "Silently block canvas access requests", and "Enforce OCSP hard-fail".
Also on LibreWolf, enable webgl.