1 cent worth:
First:
I'd like to have a "dry empty mass" sticker somewhere, even better as a basic figure in the FMGS. Would sometimes greatly help to have very basic figures. DRY + LOAD + FUEL = TOM
I do insist in separate calculations on EFB and never read the ZFM od TOM from the loadsheet or flight plan to the captain but hand him the paper to have him enter it himself. Then I crosscheck from FMGS to flight plan/load sheet and my calculation on EFB.
Has saved my day already couple times in 10 years...
Second:
Why not have mass sensors on the wheel legs? Could that work?