alt Hacker NewsRules are limited (in syntax and number) and you can only ship updated rules with updated extensions (at least you can skip the queue if you only update rulesets but it's VERY annoying to do). It's also missing a bunch of features: https://github.com/uBlockOrigin/uBOL-home/wiki/Frequently-as... (I see here that replacing response body is possible with Firefox only, is that your use-case?). MV2 was miles better.
Besides AdGuard I also have my own extension that loads userscripts from my own server (that uses the new userScripts API), so I think I only see my own point of view and the things that would potentially limit my solutions.
So far I'm able to block everything I want, but I mentioned replacing the response body because this is the only way I could modify or even inspect the service worker.. I think this vector could help circumventing ad blockers, but again - it would only matter if there were ads I'd not be able to block.
When it comes to distribution, firefox sucks because I can't even run my own extensions there, my distro doesn't package firefox developer edition so signatures are required. In contrast, Chrome let's me load unpacked extensions without any problems.