Development is in progress with a third party.
An error occurred while saving the commentDavid Golynskiy commented
I have found another workaround. Not a full fix. When I have more than 2 external monitors on my hub, then it works properly. Currently have 3 monitors and when I go into clamshell, all the monitors stay on. The main monitor switches to the external set up. And in the display arrangement the macbook internal monitor disappears.
I am on Catalina (intel CPU) with DisplayLink 1.3.0. Switching to the older 5.2.5 version did not work for me in this set up. I use a dell 3 monitor hub. 2 of the ports are display and 1 port is HDMI.