Ugh, Android VPN single-process nonsense strikes again. Trying to run Mullvad and a full home WireGuard at the same time on the phone is basically fighting the OS. Don’t waste time trying to shoehorn two concurrent VPNs or a multi-peer WireGuard profile that locks you to one Mullvad server. That defeats the whole point.

Practical choices that actually work:

• Best for simplicity: keep Mullvad as your phone VPN, and expose a small, app-level access path to your home (SSH with dynamic SOCKS, an HTTPS reverse proxy, or a tiny web app). That way Mullvad stays flexible and your home access is an app-level exception, not a second system VPN.
• If you want full IP-level access to your LAN from anywhere, use a cheap VPS as a relay or run Tailscale/headscale. Have your home server maintain a persistent tunnel to the VPS/Tailscale node, then connect to that node from your phone. Mullvad stays on your phone and you avoid double-hopping through Mullvad -> home VPN -> home.
• Alternative: put Mullvad on your home router/gateway (or an exit node) so devices behind it already use Mullvad. Then your remote WireGuard can be set to only route LAN subnets, preventing the Mullvad double-hop.

Pick the VPS/tailscale relay if you want reliability and don’t want to expose ports on your home. Pick app-level proxies if you want the easiest, lowest-maintenance setup. Anything else is fiddly and will either leak convenience or privacy.