The MMU2S does have its own board with its own stepper drivers integrated. But the board connects to the mainboard via i think uart? it needs rx and tx pins connected. And the SKR 1.4 only has rx and tx pins for the tft socket. So I have connected the dual mode screen's exp 1 and exp 2 connectors to the skr 1.4 and now the skr 1.4 is driving a lcd12864 and has the tft connector open. So now i can connect the MMU2S rx, tx, and reset pins to the tft port on the skr mainboard and get this multi material party started. Which i am doing this evening. As we speak, in fact.