I too was used to bar end shifters on some of my derailleur bikes, I think I started using bar end shifters in the 1980s before derailleurs had indexing.
With bar ends I could have both hands on the bars where both hands could provide steering capability while simultaneously being able to shift. I think that is why bar end shifters were used on touring bikes decades ago, back then it was bar ends instead of downtube shifters.
I tried a couple different ideas with the Rohloff shifter, but generally the shifter was close to the steerer tube and that hand could not effectively steer the bike. There were times on steep uphills with bad gravel and cobbles, I wanted both hands on the bars where I had better steering control, but was unable to shift because the shifter was not where I could steer and shift simultaneously. It was on one of those steep uphills with bad terrain that I decided that I needed to buy the Hubbub adapter as soon as I got home.
I did not want my cables to stick out sideways towards the headtube, but instead to go forward and under my handlebar bag. Thus I use V brake noodles on the cables as the cables exit the shifter. But I should have painted the noodles black before assembly.
