My current workaround is using powershell (on the connection server) and adding the View PowerCLI Snap-In via
Add-PSSnapin VMware.View.Broker
And then running Get-RemoteSession and parsing it to get the appropriate VM and username combinations. Connecting to the ADAM database and grabbing the data from there would really open up my options as to how I obtain the data and how it's used, so any information on why that pae-SIDString is empty would be very welcomed. Thank you!