I've never run the cables on any of my bikes with SunTour barcons under the tape all the way to the handlebar stem. I attempted that method once, and there was just too much friction, so I unwrapped the bars and did it 'classic style' -- looping out of the tape at the front of the drops before the bars start to bend upwards. I never tried it with Teflon-lined housing. Oh, and I am still using the original SunTour bare coiled stainless steel housing. Even at that, I use slick stainless inner wire, and sometimes they'll need a drop or two of 'dry lube' (high VOC graphite/teflon lube) to make them slide easier.
Installed on the '86 Miyata 710
And an older photo of the Fuji. Since this photo, the bars were re-wrapped and the cable loop is a bit higher - straighter to the downtube stop
No good pics of the installation on either of the Univegas...