Some options in about:config are grayed out, not changeable

Hello,

I just compiled latest Librewolf on Manjaro, from AUR. about:support says:

Name 	LibreWolf
Version 	84.0.2
Build ID 	20210119175354
Distribution ID 	io.gitlab.LibreWolf
User Agent 	Mozilla/5.0 (Windows NT 10.0; rv:78.0) Gecko/20100101 Firefox/78.0
OS 	Linux 5.10.7-3-MANJARO #1 SMP PREEMPT Fri Jan 15 21:11:34 UTC 2021

I've noticed few things in about:config which are grayed out and cannot be changed.

I've tested in on clean, empty profile as well as profile imported from Firefox. Firefox, same version, working fine one the same machine (these settings are not grayed out and can be changed as I please).

Grayed out are, for example:

security.OCSP.require = false (I need it on true)
network.dns.disablePrefetchFromHTTPS = true (I need it on false)
network.predictor.enable-prefetch = false (I need it on true)

I cannot migrate to Librewolf unless I can have all options I want changeable, like in Firefox. As i browse about:config, there is dozens of grayed out options.

Any suggestions?