Ability to access a VDI Collection Login Screen instead of using RDWeb

Hi,

I have Windows Server 2012 setup with a VDI Collection which can currently be accessed using either RDWeb (not ideal) or via the terminal on Linux using FreeRDP (more ideal). The problem with the terminal access is that if I don't use NLA I get connected to the Windows Server Login Screen and if I use NLA, I'll have to implement a pseudo login screen for users to enter their credentials that can then be passed  to FreeRDP.

So my question is whether there is a way to get a Windows login screen for the VDI Collection instead of using NLA and being logged into a VM directly. Users will be using thin clients which is why the web access is not ideal.

Thanks