Proxmox with one node with querier set up on "classical" linux bridge that only works in one vlan seems stable. VLAN aware bridge with proxmox ip on VLAN1, or guest connected to vlan-aware bridge's one vlan does not work.
Wireshark capturing shows windows conforms to whatever version the querier is using once a querying message is is received. The same applies to most other hosts on the network. So only igmpv1 or no querier is not okay.
My network switch only had an option to "enable IGMP", which is now tested to be only IGMP snooping.