Used Watchtower on my Synology for a while and it worked well. No issues in that time.

Now I’ve moved to a Nuc and am more experienced with Docker and understand a lot more of it but by no means am a professional by any means, I would say that I wouldn’t use Watchtower. I can definitely see it messing a config up and prefer not to deal with the headache of troubleshooting something without knowing it was an auto update. If I had the time, I may tag the apps I’m happy to auto-update but for now I prefer to have the higher availability.

From a plex perspective, there could be the chance you are transcoding. On your local network, you are probably Direct Playing on your client devices. This is seen by the dashboard on your computer's Plex app. But normally when a remote user accesses Plex, it is likely to start a transcode. This could be due to a number of reasons but most of the time it will be because the bandwidth isn't enough to allow Direct Play. Transcoding can give your CPU a workout, especially if you are software transcoding. You will need a Plex Pass for hardware transcoding which uses less CPU overall.

I'm living in the EU myself and I'm also quite weary of just downloading, but amongst friends and myself, we just use usenet and sometimes torrents with VPN and as long as we are careful, downloading generally isn't an issue.

Of course, that does mean you have to pay for a service first such as VPN, and maybe that's not something you are willing to stomach. This is definitely feasible. Your method might work but involves a lot of work to get it going and anything could take out that workflow. Downloading onto your local machine is generally going to be fine.

Look into usenet, vpn torrents and seedboxes.

Can you let us know why you want to have such a seemingly convoluted method of downloading such media files?

Why not download locally and directly onto your computer or server?

Assuming you are wanting to sail the high seas but think of the Pi in another country as a method to get around restrictions, look into the following: usenet, vpn torrents, seedboxes.

Some of the self hosting is a bit pointless, let’s be honest, but it all depends on a case by case basis. Having an automated Plex server is 100% an improvement. Got a new mini PC this week and was messing around with it and setting things up. One was adguard home and whilst it is very good, it does feel like adblockers these days do a very good job. Since I’m in the setting up phase and rebooting the server, internet on devices will go down and I there isn’t redundancy on DNS server.

I think most on this sub are tinkerers at heart and like getting the most out of it and seeing how low power to utility we can squeeze out of our gear or just the pure number of containers etc. I don’t think it matters if you use everything on a daily basis but it’s there when you need it whilst other services do their job just by being active.