With the help of the good folk here, I've got Primo 2.4 and Truck maps installed on a Chinese no-make.
The unit is working fine today and it's been planning routes around known obstructions, as it should.
Tonight I was tinkering with the settings and was in the UI Labs menu for Cockpit Settings.
I changed it from Auto/Default to Alternative 1, it shut down and restarted with a different screen lay-out, as expected.
So ...