Roon fully accessible from remote location via VPN

On a whim a tried out a Roon session from my phone via 4G VPN in the middle of the western plains grasslands of Victoria, Australia.
Worked very well!!! Amazed. Full playback on my phone.

Bog standard OpenVPN connection (different subnet) on an Asus router running Merlin firmware. Ok, so not fully bog standard.

Amazed? And actually why? This is simply math and physics.
Roon works on the network, on every proper configured network …

Many Roon users would like that.
Can you share what you did to make this work?

That is very true, but Roon is very limited in what you can do network wise.
If you do want Roon working from another subnet than the Core is on, then you have to prepare for some serious trial and error.

So actually i am amazed that VPN “bog standard” works.

Roon has not previously worked across different subnets. If you could VPN in and be placed on the same subnet then, sure, that worked.

Most VPN solutions place clients on a different subnet so Roon clients cannot discover the Core.

My set up is an almost 100% standard OpenVPN server running on my Asus router. Client or Client connection is the only additional check box I have clicked.

Chewed through my 4G data this afternoon streaming 44khz files so back to Plex Amp while on the cellular connection.