I've having some issues with this...
If I setup a VLAN (4) tagged interface as per the VM example with address assignment set to None:
I can ping my vlan gateway just fine from my unraid cli.
my ubuntu VM on br0.4 can not ping it's gateway
When I try to follow the docker example:
I can ping the vlan ip set on the unraid box, but not the gateway.
docker containers on br0.4 are not reachable
I'm also using a unfi router, setup the VLAN network to be "corporate" so inter vlan routing is enabled by default, just like in your example. Pretty sure everything is in order, the only difference from your examples is that my main unraid interface is a 2GB LACP bond.