Sounds like the 45 degree angle is torqueing (sp?) the life out of your spinnaker pole rings because the pole end fitting isn''t designed to be "skyed" that way. (All the books talk about keeping the pole level, to get maximum extension for the spinnaker.) If you rig the pole so it is level it may solve this problem. You might also try tying the snatch block to a line run through the outer end of the pole and then back to the mast end of the pole where it could be tied off at the "right" position for whatever maneuver you were doing. Not as neat as a strap, but might give you
the flexibility you need.