Hadn't thought of this reason, but that might make sense - in essence, the standard AML rules have always required specifying the final beneficiary of a payment if you pay money to someone who'll hand it over to them.
If Patreon is being treated as or claiming to be a payment service provider (i.e. it passes money through to authors without owning it in between, the only revenue on their balance sheet is the fee they take) then it'd be wrong to state that Patreon is the beneficiary of a particular payment, since it's not; and they'd be required to list all the actual beneficiaries on every payment, which can't really be done for reasons, so they need to charge many small separate payments.
On the other hand, if Patreon is being treated as or claiming to be selling a service (i.e. it takes all your money, and pays it out to authors as a business expense) then that has major tax implications, namely, all the amount (as opposed to just their fees) is their revenue and thus subject to various sales taxes and VAT worldwide. This seems to be the current option, since they're charging VAT on the full amount for EU patrons.
It might be plausible that they're currently switching from option 2 to option 1 for financial reasons, and this precludes them from batching in the future.
They can list a beneficiary on the payment, not an arbitrary number of beneficiaries. They can list a beneficiary tax residence on the payment, and that'll apply for the whole payment. Two beneficiaries means two amounts (you have to specify how much goes to person A, anyway), and thus two payments.
If Patreon is being treated as or claiming to be a payment service provider (i.e. it passes money through to authors without owning it in between, the only revenue on their balance sheet is the fee they take) then it'd be wrong to state that Patreon is the beneficiary of a particular payment, since it's not; and they'd be required to list all the actual beneficiaries on every payment, which can't really be done for reasons, so they need to charge many small separate payments.
On the other hand, if Patreon is being treated as or claiming to be selling a service (i.e. it takes all your money, and pays it out to authors as a business expense) then that has major tax implications, namely, all the amount (as opposed to just their fees) is their revenue and thus subject to various sales taxes and VAT worldwide. This seems to be the current option, since they're charging VAT on the full amount for EU patrons.
It might be plausible that they're currently switching from option 2 to option 1 for financial reasons, and this precludes them from batching in the future.