Originally Posted by BubbleheadMd
Let me re-phrase the question:
Would a brand-new, quality Dacron sail experience any "settling in" when placed under loads for the first few uses?
Yes and no.
The fabric is heat calendered from crimped yarns, etc. it will very slightly change dimensions in accordance to the normal loads applied until you reach normal 'relaxation' of the crimp. This will not be visibly noticeable; solid or monofilament dacron only has a 5-6+% elasticity/elongation at 'ultimate tensile strength' (failure).
If a seam has slipped due to poor stitch tension, then yes.