Gear cutting ratio has to be the same as the gear set ratio so it is impossible to have a hunting ratio for cutting if the gear set does not have it. High contact ratio is good for transmission accuracy but it is not always good not for the gear strength. There is another big problem with the gear. Most of them have undercut of the gear and pinion tooth surfaces. Visually they look good but the real contact area has been decreased by the gear and pinion undercuts.
Special software has to be used for calculation of undercut areas.
Variety of ratios. The ratios are limited because the pinion has 1,2 or 3 threads. The problem is the gear cutter. The gear cutter has to have the same geometry that the pinion so it has to have the same number of the threads. Unlike manufacturing of worm gears an oversized cutter can not be used.