Hints? Don’t use Docker for your own sake. Why would you, you’re already running LXC containers, just setup whatever you need inside those and you’re good to go with way less overhead and bloat.
While you’re at that, did you know that the creators of LXC have a solution called LXD/Incus that is way better at managing LXD containers and can also create and VMs? For what’s worth is a 100% free and open-source solution that can be installed on any clean Debian 12 setup from their repository and doesn’t require 1000 different daemons like Proxmox does nor does it constantly nags for a license. :)