The worry for them and probably miscommunicated from my side is that they believe need to drill in the hole for the carbon housing which for the darimo bars is very worrying.
I'd just make sure that they explicitly know that they are not to drill anything.
I wouldn't want to go and pick up the bike to find new holes that I didn't want drilled
It's really not difficult to do the di2 without a bar end hole as long as there's a hole near the shifter. Tell em to get on with it