With Crossfire and SLI being pretty much dead and all the issues with Multi-GPU i don't think a 'Power-Dock' with embedded GPU would be any good.
Going for a 10nm Tegra X1 or maybe X2 with higher clockspeeds docked and undocked and higher memory bandwidth (from 96 Bit to 256 Bit Bus width) and maybe additional RAM seems to be the option that makes the most sense, at least to me.
Going for 6GB RAM and 96 or 192 Bit Bus might already be enough. Either way, an improved SoC in the tablet would be true to the concept of Switch.







