There are two issues that completely prevent us from using the harness module - first, there is no way to make a splice. We can almost do them with blue-dots, but they don't play will with cables and bundles.
Which brings up the bigger issue - bundles don't at all work like they would if someone were actually wiring an assembly and then creating bundles. For one thing, the limitation that a wire can only be a member of one bundle is an unreasonable limitation. When we create wire harnesses, we may have 10-12 wires that originate in one area, with 2 or 3 of them running the entire length of the harness, but with others breaking out in multiple branched areas. A bundle needs to be something that merely collects multiple wires into one routed path. And one wire may absolutely be a member in more than one bundle. I've been waiting for a useful harness setup since ST5, and am still waiting.
I'd be glad to discuss this with you and better understand some of your requirements. Please email me directly at email@example.com.