I have a 13' sail boat (starwing). The boom is 6" longer than it has to be.
Is there any reason not to cut it back? Sure, 6" inches isn't all that
much, but I figure it would be better shorter.

The only drawback I can think of is that I could not use a sail longer than
the original, but figure the odds of ever having to do that is slim. (the
sails are in better condition than the hull.)

So, should I cut the boom down, or is it being destructive?