As Uncle Ricky says, the ball end is generally to stop the lever stabbing you/someone else, although it can also help stop your finger/s slipping off in really sh!tty conditions too... obviously not that many people will be entering competitions with their Teneres (although the big-bike class in clubman rally events would be fun), and as has been pointed out, with wraparound hand-guards, it shouldn't really be a problem - but rules is rules...
Anyway, for anyone else interested and more patient, here are my original cut down levers, and the ASV versions, for an idea of length...
J xx
ps. if anyone is having to use the clutch a lot off-road, I'd suggest lowering the gearing slightly - I never found the clutch action particularly heavy, even with the shorter lever...