hmmm ... I don't think so. That would be total chaos and be of disservice to the argument. The idea of start-many is to simplify things, not to make it worse. With typical start-many, 1k addresses (each with it's own vin) are created, which makes it easier I guess, but since it's the first address that gets payed, it's kind of like the same situation, you can't really tell from incoming payments from which MN it belongs to.
So, I assume the way to track down each MN will be the same, as it utterly dependent on the vin, not the pubkey.
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