If fitting aftermarket wheels would tend to make the Brompton brackets fail, I would place a big question mark on the fit-for-purpose design. I don't for a moment expect it to fail. I expect it would fail if you decided to sit on the saddle with the thing folded, but not resting on the little wheels regardless of the stability base. And even though I am honest, in all fairness I wouldn't hesitate to swap back to standard brompton roller wheels if I knew a dealer would try to weasel out of a warranty claim unconnected with those wheels, but used that as an excuse.
The issue I have tried to address/discuss is whether a manufacturer should be responsible for third-party modifications that do not conform to the product's design parameters.
My concerns regarding the suggestion to basically defraud a manufacturer did not have the qualifications that you have espoused to potentially justify such action. I certainly acknowledge that our world includes dishonest bicycle dealers and dishonest bicycle consumers. However, I believed that neither group should be encouraged by postings in this forum.
-HANK RYAN-
Norman, Oklahoma USA