The native Microsoft RDP Client offers the feature
"Use all my monitors for the remote session"
Currently the CA PAM RDP applet does not offer native multi screen support.
In fact, even when you configure the session to "full screen" it outputs to the primary display only.
How can we achieve the similar functionality in CA PAM?
What you can do, is to change the (default) resolution of the RDP applet to e.g. 3000x1200 - spanning the resulting session across both screens.