I use to use a 48" turf tracer to mow a hill at the landfill and from the road to the top of the hill was about 30-40 feet and the hill was probably half a mile long, turf tracer handled it no problem. The trick is to keep the nose up when turning around and mow it at a slight upward angle almost like how you would drift a car.
Well then you ain’t mowing right. I can run a turf tracer 60 on almost vertical hills without a problem. Technique? Turn up never turn down and keep good tires on the mower also go really slow and if you have an object do a very mild turn around it. Skip a stripe if need be