I gotta reply back from GOG on the missing LSL6 Vesa/SVGA;
"Hello, thank you for your concern, but we already have access to this version. We didn't release it due to technical issues. We just weren't able to make it run swiftly on modern systems.
This of course doesn't make much sense. In my experience the SVGA version actually runs faster and more efficiently in Dosbox .74 than the VGA version, even at full screen.
It doesn't work at all in ScummVM.