ASRock seems to be the champion of motherboards with gimmicks. This mini-ITX desktop PC motherboard:
has an eDP port for connecting a laptop-like display to the iGPU, ostensibily for mounting a side panel display _inside_ the case to show through the window on the case, as the cool gamer kids do.
This associated product seemed to be on the market for 5 minutes but seems to be discontinued, or never actually fully went to market in the first place:
The port on the motherboard is 40 pin but accepts an 88441-style male plug, not directly compatible with common eDP laptop panels I don't think. And comparing the pinout in the mobo user manual they've used a variant this standard 40 pin eDP pinout:
but the pin assignment is reversed top-to-bottom. Also as I understand it eDP doesn't have any standardized way of controlling backlight brightness there are a couple ways of doing it and one would have to probe the motherboard port to find out which method is being used it and then either find a compatible display or implement one's own backlight control hardware.
That is to say I just want to make sure they really worked to make this port useless without their bespoke hardware so I don't have to waste any more time thinking about interesting things one could do with an internal eDP port if they hadn't done that, thanks!