Federation can solve the danger zone content for you, how about a federation network with just kids content, other with more adult ones, etc to the just nsfw isolated from each others?

it has something like ‘-no-remote -p name’ param on cmd that you can do it seamless like chromium, or u can use the fork of the drop official pwa firefox support, it could be better, i know n i get it, but if u just use chromium base for it, than i got u covered