Oh, thank you for the answer. That is quite odd! I hope someday that restriction is lifted.
If multiple NX clients are able to view in line with this section just above that part of the EULA:
“(ii) a reasonable number of Devices may remotely connect at the same time for the sole purpose of simultaneously observing the same graphical desktop session of the Apple Software that is running and being displayed on the Home Mac, as long as they do not control the Apple Software in any way”
And if the connection goes to that ‘choose user login screen’ then all it would need is some unofficial patch to re enable control and multiple users could connect and control simultaneously.