I was close to buying Microshift 11 speed bar end levers. I found a set of Dura Ace 11 speed, barely used, for $70 shipped. They are index only.
I do use Shimano bar end models bs-050 and bs-6400, both set in friction mode, and have used them for 8 thru 12 speed cassettes. They work great, took a bit of time and use to get efficient with the short travel of the lever for 11 and 12 speed cassettes. I do not race, or climb aggressively, if I did, I likely would not be as pleased with the friction shifting. The 6400 is being used for a 1X dtivetrain, 42 tooth Xsync ring with 12 speed, 11-40, Sunshine cassette. The handlebars are Velo-Orange Porteur and Left Bank bars.