Yes, I agree with Dennis.
Apart from that you said "I would like it to look right in 3D views and whatnot for clients. Typical design: diamond12x12 above mosaic strip 6" or so, above 16x16 squares... how do I do this in Chief? Or can it be done?"
I think in this case you may use glass-tiles-backsplash (that are easily a\found from stores as wholetiles) for making a kindof 3d view. For more its better to contact with anexpert who can give you a better idea of it.