the independent vaulting is the real feature here. most billing tools tie you to one processor's tokens, so a MID shutdown means re-collecting cards from every customer. PaymentKit vaults tokens under their own TRID so you can add or drop a processor without touching the customer at all. the maker's launch thread also goes deep on VAMP dispute-ratio thresholds being measured per MID, which is a genuinely underrated risk most SaaS teams don't think about until it's too late.