When you hear a Middle Office executive utter the phrase "we are custodian agnostic" it clearly implies they don't care which custodian you choose to partner with. We make it our business to care and we take pride in knowing the differences between the custodians. We are custodian specific.
Our Middle Office partners have relationships with all the major custodians and are not bound by contract or understanding to do business with one over another.
Some Middle Office execs are famous for saying "we beat up the custodians so we can get you the best price". We don't "beat up" our partners.