Originally Posted by Redbullet

The hanger is around 25mm, so, within requested limits.I bet mine would also work nice with 11-32. Finally, B screw does adjust the pulley up, but not more than total 3-4 mm (therefore, I did not observe at the beginning). But 3-4 mm is not enough to cover the interval of large cogs (25 to 34 teeth) for which Tiagra was designed. Thus, it was optimized for upper range (30-34 teeth) on a standard hanger. Once you go toward cassettes with the large cog of 25, B screw can not compensate and shifting starts to deteriorate. I think this is rather a poor B adjustment design than a malfunction.
SRAM solution is way, way better: I regularly switch between wheels with 11-26 and 11-32 cassettes and all I must do is to rotate B screw +/- 8 complete rounds to adjust upper pulley position, then shifting is crisp with selected wheel. And I still have “B adjustment” unused.
With Tiagra I must re-optimize around my big cog of 26. But since “B adjustment” is not enough, I must find another hanger (around 1.5 cm height instead of recommended 2.4-2.6), so the upper pulley will be closer to the cassette. I do not even know whether such hanger exists…