I use an LXC to run Docker and a bunch of containers on my Proxmox VE machine :). LXC is interesting, but you can't beat the ecosystem of Docker images available (and maintained, updated, etc.)
Have a few apps running in plain LXC containers (like AdguardHome) but maintenance is non-free (unlike a docker-compose stack with Watchtower keeping everything nice and fresh).
What do you mean by Watchguard? I did a search but didn't find anything. Did you mean Watchtower maybe?