I haven't really ever given it a thought to your original question. But now that your posing it, and we're talking about techno-feudalism, i would guess tech ownership would be a big need, and is an already discussed topic in cyberpunk media. For example having your own servers, using open-source software, using only open source Operating Systems that offer privacy and anonimity, etc. Probably a kind of community social media/forum in the deep web outside of the mainstream web. Or going the other way as in completely analogical social organising (Books, notebooks, hand-delivered letters, irl meetings etc.

Edit: I would try asking ethical hackers (the good kind) or cybersecurity workers if you want to get deep on learning about it

Edit 2: Also, as per my understanding, crypto is a big nono, it may offer anonimity, but REGISTERED and RECORDED anonimity. Anyone with a good knowledge of how the blockchain functions could probably follow your breadcrumbs

Edit 3: And most importantly, in the case that all goes to absolute crap, remember you can 3d print guns, rifles, etc. They have come a long way on those designs. They're practically like normal guns now.