if needing the pto.. you can't use idle.. you need rated speed. at rated speed.. 1st may be too fast.
even in the old fords with trans pto.. the addition of a sherman low let you tach the engine up highand get pto up even though ground speed wasn't ideal.. still
I always wanted a sherman step up step down when I had the 8n. The gearing was terrible on those tractors, reverse is the same as 3rd gear and low is too fast for some things.