First, I'd have to get them talking to each other. I am not an expert at Docker, and I just do the most basic stuff with it.

And second, I think they'll need to be reachable from the web, so I'd want to host them somewhere out in the cloud, and not on my home network. NearlyFreeSpeech doesn't offer Docker hosting yet (that I know of) so that means paying more for somewhere else for it...

And at that point I decided I didn't care enough about the benefits to deal with all the downsides, and just signed up on a Lemmy instance. It was actually the second instance, because the first one had stability issues. I then realized I didn't like how that instance was being run, and signed up on third, which I've been happy with and it's been relatively stable. At least, when it had problems, so did most other big Lemmy instances.