I can’t believe it was so simple, and I missed it for so long.

After referencing and importing mpsLLC71.dll into the namespace, you add:

Shell("C:\Program Files\MPS\Prolog Manager 7\Program\mpsRbl71.exe -q -u", , True)
Dim reg As New CLicV3Com()
reg.SitePath = "C:\Program Files\MPS\Prolog Manager 7\Program\"
reg.RegisterToServer("\\your-license/app-server-UNC-name\MPS\Prolog Manager 7\Program\")

completely silent and working Prolog license registrations!

sounddoc