Hi Bill. I have heard you say before that you wouldn't use vertical battens with our in mast furling. I've had mine for 8 years and have had no problems furling them or with chafing of the sails or pockets. The battens are 1/4" thick and 1" wide. I can furl without problems even when the wind isn't on the nose by rolling it up so that the battens are on the outside of the roll (so that the battens don't have to go past the edge of the slot in the mast...if on a port tack I furl in the direction that rolls the sail onto the port side of the foil...there is plenty of room for the battens to clear the slot.)
I lost a batten once, but the bottom of the pocket was not sewn properly. Other than that I've had no problems at all.