Ron - I've left space behind each shelf so that cables can be routed vertically with no trouble. What I hadn't accounted for at the beginning is a way to keep them tidy. I now have an idea for that, but it's still not clear if it would be overkill for the small number of components.
Cables will enter/exit the cabinet through the lower rear stretcher. I haven't settled on the details, but the current idea is to recess a brush panel or two. I have a set ordered to evaluate. If they're not appropriate, it's an easy Amazon return. They're a bit bulkier than I'd like, but there's some question on whether a 1u rack-mount brush panel will pass a large power cord plug. But I'm going to order one of these to check out too.
Regarding SU vs Onshape, I hop back and forth. Given my limited proficiency in both, I find that SU is better for a quick model, where Onshape is much better for refining a model, especially when curves are involved. Of course, I'm using the free version of SU 2017, so maybe it's improved since then.
