In fairness to multicolor printing in general, he couldn’t have picked a worse multicolor model for generating waste. You want to optimize for as few color changes as possible. Just the other day I printed some pokeballs in full color and it was (iirc) around a 0.4:1 waste:print ratio - which is still a fair bit of waste, but nothing like 2.5, thanks to the fact that the colors are layered.
Gradients are the absolute worst thing for multicolor printing, this printer was probably doing 3-6 color switches per layer
Onshape is also good, the free version has all the functionality you could want unless having private models is important to you