multiple bridges

I have multiple interfaces going into PVE. My server has the following interface built in (Primary: enp87s0) which does not have native drivers built into the kernel. I've been able to install the drivers and get it working on 192.168.1.75/24 (vmbr0 on PVE). For redundancy, I wanted an interface...

I have 3 NICS connecting to separate Routers and out to separate Internet connections. I have set up the additional bridges vmbr1 and vmbr2, given them the required subnets and linked them to the physical NICS, see screenshot. vmbr0 has the 'Default Gateway' on it, and I know I cannot put...