Shift Point

trial and error is what it will take to get it right. There is not one right answer here.

if you peak 6100 and then the HP drop like a rock.....you had better be shifting sooner the 6100.

If the peak HP fall slowly, then running above peak might be advantageous.

shift 500 before beak, make 3 runs, shift 500 higher and see what your ET slip tells you.