Android does not allow to keep a SSH tunnel open while an app is inactive. So we could open the tunnel through Royal Server, but as soon as we switch to Microsoft Remote Desktop Client, Android would close the tunnel again to save battery.
If you need to connect via RDP, then you have to use a Remote Desktop Gateway. We do pass the parameters for the gateway to Remote Desktop Client.
All the other management connections which connect through Royal Server like Windows Services, Windows Processes, PowerShell, ... are handled directly between Royal TSD and Royal Server. These work as expected.
We also plan to include a Terminal connection directly within Royal TSD. As soon as this is run within our own app, then we can also use Royal Server or any other SSH gateway to open a tunnel. But this only helps for SSH, not RDP.