I think I've experimented with rotating the bars on almost every bike I've ever owned, where it was possible. It's cheaper to try that first before ordering risers, and easy to test for interference from tank, cables, etc. Maybe worth a try. Remember that the bar-ends will move in an arc, so changes in the distance to the seat will be small, and as you rotate them upwards, they will at some point move farther away despite being higher. I just looked at mine and, although I remember playing with them, they appear to be at the stock position now, so I'm guessing I couldn't make them any better for me (that was 5 or 6 years ago). Everyone's ergos are different. On my R9T Scrambler, I ended up getting OEM risers (BMW called them something else).
You only need to loosen the 4 bolts a bit. When re-tightening, torque the front ones first, then the rear ones. There should be a gap at the back and none at the front. Torque for mine (2016) is 19 Nm.