One year ago when I got this bike I posted in this thread asking if anyone has done the conversion from mechanical ultegra to di2. There were people advising going with E-Tap as it would be easier or that the frame wasn’t compatible .
After doing some research and talking with Canyon, this mechanical frame is absolutely compatible with di2 as it has the holes already pre-drilled for the front derailleur and the holes for the battery holder in the under the downtube.
You only need to purchase a Canyon GP0274-01 Battery Holder that will fit the battery into the downtube. I purchased a bike frame plug from Aliexpress to plug the extra holes and had my local bike shop put it all together. Hope this helps for those who want to upgrade their bike to di2!
by ey6616