once the epoxy on the wood is dry, apply unidirectional glass tape. One layer is enough. 1m is about 20 cents. One piece of would (2m) is about 1€. Hence don't hesitate to make some prototypes to find the right thickness to get your desired bending curve. For long battens I start with 4mm and plane down to about 2mm at the tip. 4mm is already quite stiff.
Round the edges to protect your sail and make some spare battens as well (Never broke one while sailing, but once my crew felt in the sail after pitchpoling and one batten was broken).