If you have a router like OPNsense/PFsense (but I think that OpenWRT can do that too, I've never used it) you can forward all your home traffic to Mozilla VPN so that when you connect home with your home VPN you can reach your LAN services and at the same time Internet through Mozilla VPN.
But if you have a routed Android smartphone (or a PC), you should enable both VPN allowing LAN only traffic through your home VPN and all the rest (you can use this to calculate the subnets) through Mozilla VPN.