[6.10 - 6.11.1] IPVAN + "Host access to custom networks: Enabled" causes unraid to lose the ability to route externally.

Going by this thread here, I believe this issue to originate with 6.10 when ipvlan was introduced.

I've just recently needed to switch from macvlan to ipvlan as my sever started kernel panicking after adding some new hardware (nvme+ram).  if 'Host access to custom networks' is Enabled while using ipvlan the server functions normally in terms of routing, reaching the internet, etc, and the routing table is all good:
 

root@vault13:~# route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
default         10.81.0.6       0.0.0.0         UG    0      0        0 br0
10.81.0.0       0.0.0.0         255.255.255.0   U     0      0        0 br0
172.18.0.0      0.0.0.0         255.255.0.0     U     0      0        0 br-f237a61f1b1e

After starting the docker service, the shim interfaces get added to the routing table and everything seems fine:
 

root@vault13:~# route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
default         10.81.0.6       0.0.0.0         UG    0      0        0 br0
10.81.0.0       0.0.0.0         255.255.255.128 U     0      0        0 shim-br0
10.81.0.0       0.0.0.0         255.255.255.0   U     0      0        0 br0
10.81.0.128     0.0.0.0         255.255.255.128 U     0      0        0 shim-br0
172.17.0.0      0.0.0.0         255.255.0.0     U     0      0        0 docker0
172.18.0.0      0.0.0.0         255.255.0.0     U     0      0        0 br-f237a61f1b1e

then after a minute or two of the docker service running all internet routing from the server comes to a halt, except for any containers on a br interface with their own IPs.  Another capture of the routing table at this point doesn't show any changes from above.

The only work around it setting 'Host access to custom networks' to disabled, but that's a not ideal.