When I do that it just changes reel speed I think.
The indexed reel speed works a bit better but generally not as good as MOST combines do.
Well that may be, but then my CR9070 with Honey bee header does not fit in your MOST category. I feel the reel indexing on my m 150 is way better than on my combine. Combine does not use an actual reel speed sensor, but must go off oil flow. Oil flows much differently at different temps, but combine does not seem to realize this. When you start out for the day and oil is not fully warmed up reel is going twice as fast as when you shut down the previous day. Needs lots of tweaking, not a set it and forget it. TR 99 was far better.