Hi Alex,
Thanks for the response. Yeah, I'm aware of the RDP plug-in, unfortunately it isn't the most responsive or well-built plug-in. I've had much better luck in terms of remote desktop performance via VNC or Chrome Remote Desktop (on non-GCE boxes), which is why I've been trying so hard to get either to work, and why I posted this potential solution (not 100% if it'll work) - assuming Google could look into it.
I presume that since both CRD and VNC have the same issue (black screen) that it's probably related to the same underlying issue (no graphics adapter), which may or may not be something Google techs could add to the VMs for Windows... dunno.
Anyways, yeah, I'm not looking for immediate resolution, just something I had hoped worked out of the box.