Why a new arrow?
my thought was if the bow is being over strained because of the "longer" drawlength (because reflex was added), then thinning the limb some would reduce the strain.
This of course would reduce weight and call for a lighter arrow to be an equivalent test.
the reduction would be effective if the bow has not taken too much set, but, as you say, the wood might be getting tired so the results could be inconclusive.