Reading about Long EZs, I came across a bit about gross weight, which led to this POH:

On page 30/39 there is a bit about "over-gross operations", which leads me to asking some questions about gross weight in EAB aircraft.

In the case of this over-gross (1420lb) vs gross (1325lb) weight, which would be considered the gross weight for the purposes of the data plate?

What testing would be required for weights within the over gross section during Phase 1?

(And this one is just curiosity) If an owner (that does not hold the repairman cert) wanted to change the gross weight of an aircraft, could it be done, and if so, what would that process be?