I'd suggest starting now because you are going to want to have your U1 busy with multi color prints. Multi color tpu is amazing. I made a mini chess set with tpu and the pieces feel fantastic.
U1 tip: make sure all the plastic trim is snapped in inside the printer, especially behind the toolheads. It took me a month to figure out why my toolheads sometimes didn't park. It looked fine but with more pressure I got a click and haven't had problems since.