Simply question - I understand the new macs support a max of 2 displays. When the lid is open, that means you only get one external. If I'm in clamshell mode - can I support 2 4k displays?
Depends on how you connect them. There is a tube video where a guy uses a Targus HUB and runs Three screens. The uses the display link protocol. And he shows that at least it all works.