There isn't much hassle other than possibly creating a harness and using some decent connectors. The cost could be in connectors or tools needed to make the harness. Just extended via soldering doesn't add much cost, but certainly adds a lot for time and more possibilities for mistakes.
If you do make something really high quality I'd be interested in buying a section or to and then making the rest myself to accommodate my personal preferences. The energy required to R&D this own my own vehicle is just not there. At this point, I've got irons and no fire.
You are ignoring content by this member. Best. Feature. Ever.
We had a much more sophisticated version of this, custom developed. And....Then the compatibility bugs came, board software updates and any time you start screwing around with custom permissions that is never going to last for a long time in terms of being stable so I wrote it off as lost development costs and have focused on other things so hopefully the Ignore feature provided is sufficient.