I'm well aware Nvidia only provided the Tegra X1 for the Nintendo Switch.Nvidia had nothing to do with the motherboard in the Switch they just supplied the SOC
The only reason I mentioned "...or paying Nvidia to design and manufacture, a much smaller and more compact motherboard..." is because that's what Nvidia has done with the Jetson Xavier NX, where the die size of the Jetson Xavier NX is 350 mm².
I think the DLSS model*'s motherboard's going to be very similar to the OLED model's motherboard design wise. But if Nintendo for some reason decides to use a much smaller and more compact motherboard for the DLSS model*, I expect Nintendo to spend more money on designing and manufacturer such a motherboard rather than paying Nvidia to design and manufacture such a motherboard for Nintendo.