My guess is you are using a low stretch string like poly. Start with you weight down and left it slowly in small increments and let it down slowly.
But then how do you clamp a single string with flying clamps. if you had a starting clamp you could clamp the right main outside the frame with the SC and tension the left main then you have two strings to clamp.
Everyone has the right to be stupid... it's just that some people abuse the privilege