Topbunk... understand what you are saying, but that is a paperwork reason as opposed to a actual structural reason. I am wondering if there is any documents out there going in to this?
Wether the weight in the wing lockers is fuel or baggage, the wing root bending moment will still be the same, so physically it will not make any difference.
Possibly different ZFW with the wing locker tank mod, do not know.
I do not feel that fuel distruibution, c of g will be an issue, as there is no limits to landing with full fuel tanks, as long as you are below max landing weight, which is only 45kg below take off weight.
Burning off fuel in wing and aux tanks does move the cof g forward, so having baggage in the lockers and not fuel would actually improve matters