A couple of weeks ago, I gave Shangai GP3 a try in one of my Holgas. The result was also frustrating like with the Fomapans. The scratches are all over and along the film. I developed it in HC-110 and the negative looks quite nice. Perhaps, I will try another roll of GP3 more carefully, but I see another cheap film useless for 120 Holgas.
Up to the moment, 400TX, Acros, HP5+ and FP4 are the films that work without scratches in my 2 Holga GNs.