So after deleting the Virtual IP, clearing the "IPv4 Remote Network(s)" fields on both of the OpenVPN configs and adding in Static Routes for the remote subnets, it seems this is now working and the Static Route persists between tunnel reconnects. For some reason it still doesn't seem to work without defining a Static Route for the remote subnets to route over the VPN Interface gateway, but nonetheless, it works!
Would have never even considered to look in the Virtual IPs, thanks for your help @viragomann