We have short battens on our 27 and get the same annoying issue with the lazy jacks,one batten near the head being the particular culprit,which often requires lowering the main again ,and sometimes unhooking the line with the boathook.
I thought that this projection was provided so that you could apply a force to the batten end so that a tapered batten such as found on a windsurf sail would snap to an aerofoil profile,but this wouldnt seem to apply to battens of constant section.I suppose over a period with sail stretch a flush end at the leach would no longer allow you to fully tighten the batten to the pocket or give you anything to get hold of when removing a batten.
Perhaps having slack in the fit of the batten would allow a movement that would wear the sail unduly.
Peter