We recently tried the MIG instances.
There's just no way to use them with VMs, but with LXC containers they seem to be working. Prefererrably with Nvidian container toolkit so it's simplier to mount the to containers config by using the MIG instances IDs.
The MIGs for VMs would require the paid Enterprise AI license for VGPU feature, but that's not yet officially supported with Proxmox and H200 card so not sure if this would work.