If you're already using LXC containers why are you stuck with their questionable open-source and ass of a kernel when you can just run LXD/Incus and have a much cleaner experience in a pure Debian system? Boots way faster, fails less and is more open.
Proxmox will eventually kill the free / community version, it's just a question of time and they don't offer anything particularly good over what LXD/Incus offers.