I'm working with a complex (spline-driven) ~100mm length part and keep running into issues with after many operations geometry which should be touching just barely isn't (i.e. the intersection line of two complex surfaces being ~.0005mm off of the surfaces). I've begun to wonder if accumulated round-off error is the source of my problem. Is this reasonable to suspect? How might one address this?

Would working on the part at 100x scale, and then as the last step scaling it down 1/100x maybe help?

What units does SolidWorks do its internal calculations in, and are numbers 32-bit floats?

An aside, I know splines are not mathematically complete, and that the offset of a spline can only be approximated with another spline. (see: Bézier curve - Wikipedia). I'm sure this also causes rounding error in complex parts.