Pre stretching cable/ Prop differences
I don't know what kind of cable you are using but I have used nylon coated braided steel fishing line for years--all the way from 30 pound test to 120 pound test and it does not stretch. I don't even notice a change with extreem temperature changes. I have also used 50 lb. test nylon leader on both elevator and rudder on a quarter scale Cub with no evidence of stretch over a two year period. I was always leary of the nylon leader material so watched it closely for any ill effects and found none.