Okay, so what I ended up having to do was to re-install Brave, download the extension for Brave (which Google doesn't block), and then simply drag the file from my Downloads folder over to the the Dissenter browser and let it install. No problem.
Clearly, the issue is that Google is trying to block Dissenter. I wondered if they'd go so far as to actually refuse service from the Chrome store, and now I know. They'll do anything to clamp down on Gab and Dissenter.
Hopefully, others will find this useful as more and more censorship creeps across the net.
