So about 15 years ago or so I bought some Kelly Take-offs with the idea that I would use them on my wife's bike. I opted for STI's. Tried them on another bike and hated them and tossed them in a bin.
However, I ended up putting the Take-offs on my road bike until I could find 8 speed non-Claris STI's (came close to using Tiagra 4700's, but that's another story). Everything shifted well and I am acclimating to them. It helps that the DT left shifter is spring loaded Ultegra, and the right is indexed.
I started having shifting problems and it turned out that the stupid noodle setup wouldn't accept a ferrule for the shift cable but the strands were pulling through; which I should have seen coming. I decided to use some Jagwire 5mm brake housing despite some misgivings. It is about 16" to the DT boss cable stop. So far I have not had any problems with the indexing and it is nice to keep my hands on the bars despite the required gyrations.
I think these are the original 4mm, but they are now 5mm.
John