I'm sure you know this, but it is quite common for " standard " rigs to be non-standard. Don't know why, but they are. Sail makers ,for this reason, don't take anything for granted. For my new working jib
, I hauled luff and leech cord to the height I wished, and tied off a foot cord at the wished for tack position. This gave me flat plane dimensions. Sail maker make cutting size adjustment for future stretching. A good sailmaker
will send you a drawing showing horizontally, every 10% of luff height, where they intend to put the draft
with leech and foot lines unloaded. Increasing the area of the sail will affect Cof E and CLR balance, and therefore sheet trim.