It’s a new bike so I’m wary of drilling a hole into the frame or trying to widen the already existing one where the mechanical cable goes through. I just don’t want to give any reason for an invalidated warranty claim if I ever need to, or even to potentially weaken the frame by my efforts of drilling or expanding a hole.
I think I’d rather take my chances with the splicing because if I fail at that then I just have a 1X and the Di2 cabling is cheap so if I screw up it doesn’t harm the bike and I’m not out much money.