XRDP to always use a new session

What are you doing on the remote system that needs the full desktop? There is probably a sleeker solution to what you are doing...

I don't want the full desktop, I just want to be able to launch a custom QT script. I tried with x11vnc but there were a bunch of opengl errors and I couldn't get the QT to work. I am able to get QT to run over x11rdp, but I want to give about 200 people access to it so they can access this in house training tool we've built. Right now they'll steal eachothers sessions rather than launching new sessions for each agent logging in.

Have you tried using SSH and X forwarding? The application will run on the remote system but will display on the client system. If the client systems are also Linux based then this is as easy as running:

ssh -X username@server command

Note that the X is uppercase. Obviously change the username and password and use the name of the command to run if it is in the path variable (or use absolute paths if you like). Eg:

ssh andy@app01 firefox

And the browser will launch but will be using the resources on the server (a bit like Citrix in Windows).

I figured it out, I set the Policy=UBDC in sesman.ini