Using Watchtower for approximately 2 years on about 20 Containers. I had 1 issue, where a container would not start after the update. The Error Message said I had an unsupported entry in the configuration file of the app. I looked up the changelog of that app, and found out that the option was removed and replaced by something else. Had to change one line in the configuration. Not really a problem for me.

Though I decided to exclude my Home Automation Container and my kasm container ( my gateway to my network, a bit like guacamole ). Those may pose problems if they are offline unexpected.

Actually you could remove most of the drawbacks if you split up your gpu (there are multiple technologies which enable you to do that, but your gpu would need to support at least one of them) and give each of your friends a virtual machine to play on. That way everyone could play at the same time. Though you get a new drawback : the experience would certainly be very limited if you share the GPU resources with multiple VMs. I think VRAM is fixed so if you have 16gb of vram and two virtual machines each with 5GB of VRAM you got yourself 6GB left, no matter if someone is actually playing on one of the VMs.