@Derelict I assumed having gateways defined would allow the network to smartly know the route to take and so having them on the same subnet would work. Literally never had to think about subnets until this week.
To test, I ended up doing all my Lan stuff on 10.25.1.x instead with a Xen Private Network. Once all the VM's worked, downloaded the configuration from pfSense and did a search replace on the rules before 'restoring' the xml file and swapping the modem cables over.
Got the home network running on a virtual pfSense okay at the moment, bare a few weird dns issues with kube-dns and dns resolution from pods. This will make it easier to move to a physical machine once ready. Just hope Xen doesn't crash at all.