Meh, it's just Firefox with a config applied out of the box and some new branding. They don't really patch anything of importance out of Firefox, pretty much all of their patches are just changes for their branding/styling.
Which you will most likely be able to disable with a policy.json just like Librewolf does with Pocket and other Mozilla services. I personally rather just build Firefox from Mozilla's sources and use my own configuration rather than having to put trust into some third-party to do that for me. Though I understand that is definitely not everyone's cup of tea, so I guess Librewolf is good enough for the majority of people. Though I'd be weary because a lot of the settings Librewolf enables (namely the things under privacy.resistFingerprinting) break a lot of websites which some people may not want to deal with. In that case, I'd just take Arkenfox's configuration and remove all that stuff from it and call it a day.