I'm working with the most expensive individual parts I ever have. The materials are expensive, the processing is expensive, and there aren't a huge number of suppliers capable of making these parts. Plus, since there can be six months between ordering and receiving the part, there can be some resistance to change. The challenge is when additional sensors, tubes and brackets are added later, there is nowhere to bolt them to. The solution is to future proof the design.
In high volume manufacturing these extra features might be scrutinized so much that it is not possible, but the again I would hope you are working with all of the requirements from the start (and I mean how sensor X is going to connect to location Y) because in low volume manufacturing that is often not the case. The ancillary systems are added in later after the bulk of the design is complete.
So this has been frustrating me a bit because I can see that in the next six months there are a lot of things we will need to add to one of our products and there aren't many places to add them. Years ago I owned the engine frame design for a large off road vehicle, and it was extremely eye opening how probably every other day someone would have a request to add a clip or a clamp, and this was just a few months before going to production! The solution was to add a few extra holes and mounting features in possible locations that might be useful in the future.
In short, if you ever are responsible for the design of a core part or a base part of a product, add a couple features so that when someone else comes by later and needs to route a wire or a tube they have a place. It's easier if you ask yourself the question before releasing the part, "will anyone ever want to attach something to this part that I was not expecting?"