I do not have electrical drivetrain, but I love classic framesets with modern groupsets. IMO, there is no such thing as morality regarding the building of any bicycle. Build it how you want it, with components that work for you. I had a late 80's frame set that I purchased when new. In 2017, I stripped it to bare steel and had it powder coated. I rebuilt with the DT levers. It's not that I dislike that set up, but I rarely rode the bike, opting to ride a bike that had STI levers. I replaced the DT levers with STI levers and never regretted it.