General statement -
As long as you can tie the battens on the mainsail then in theory it doesn't matter how long they are, from a too long standpoint. "In theory" You don't want them so long that they interfere when you take the sail down and haul it around, but the length shouldn't affect much functionally.
The jib is a different story, the battens do catch up on the mast in light wind, other than using non class legal battens there isn't much that you can do, other than trimming them to the minimum length to allows you to get the batten tension that you need. Mine stick out about 1.5" I may trim the upper battens just a little, but I only have catch ups in pretty light stuff, sub 5 knots probably. and it is easily correctable by man handling the jib over to the other side.
Cesar (Cez) S.
H16 - "He gone!"