I kind of take it as a “shift now” and a “shift NOW before you blow up!” setting. I’ll have to see what mine is set at - I’ve never noticed it coming on. On all my previous bikes I shift by feel and seldom looked at the tach. Don’t really miss it, either, except it looks strange without it and the speedo being mounted off center. I made a bracket and centered it but eventually put it back to normal. Crowded the key too much for my chubby hands.