Are there steps that might be taken early in the build process to verify that the engine harness has been assembled correctly by the supplier?
Are there similar factory-/supplier-related weak points that warrant checking in the kits, rather than assuming things are going to be OK out of the box (crates)? Volt meter connectivity tests comes to mind, but is that feasible and comprehensive enough?
And is there a good set of wiring diagrams available? I've seen the ones in the 2015 Build Manual, but they're not very clear - at least, after an initial look.