I too believe the restrictions on the 300 will scarcely be noticed by
the average pilot, but if someone is concerened (acro) their ship can
easily be proof-loaded to 5.3 G's. Stan Hall wrote a good paper on
just how to go about it, published in Soaring. Basically you mount the
wing inverted on a sturdy test stand, secure it so it won't twist and
then sand-bag that puppy to the flight limits, usually 5.3 G's. Then
you know the wing is stong enough for anything it should see in flight
if the ship is flown within the flight envelope.
JJ