Originally Posted by Liquorice
...and the outhaul controls draft depth, not sail shape. It's not a substitute for the mainsheet. This might contribute to your premature mainsail delamination if the sail has been flogging a lot. The clew should be sliding close along your boom on a slug or track.
I suspect you might need a little help with sail trim.
Aren't sail chord depth and draft what sail shape is?
On many modern Bene, Jeanneaus and Hunters, the track on the boom doesn't extend all the way to the mast. When heavily reefed, there is a pretty big gap between the boom and the clew. I do not know why they are engineered that way.