Wasn't there also an issue with WMUK processing payments, in that they
couldn't pass 100% of the donations on to the WMF but had to retain some or
most of the funds in order to remain independent under British law? That
seems like a good reason why the WMF might not want WMUK to process
payments, and the byzantine ruleset they'd have to abide by to have a
regime of chapter-based processing is a very good reason to avoid that
model in general.