Multisig and Bitlicense???? Can a business even be a custodian? Lets say a company like BitGo controls one key in a P2SH multisignature address, are they a custodian and subject to the bitlicense?

For enforcement, is it even possible to tell if someone is being a custodian if they use bitlicense?

Any insight appreciated
This falls into an explicitly gray area, as called out by a number of people when bitlicense was first adopted. For example, see; https://twitter.com/twobitidiot/status/606157758224834561 and the linked tweet. Also see: https://coincenter.org/2015/02/our-initial-thoughts-on-new-yorks-revised-bitlicense-proposal/

Practically, if you're not acting as a custodian, then it's unlikely to be enforceable, and they will leaver you alone. If you are, effectively acting as a custodian over the funds, it is possible that NY could choose to go after you - and they have expensive lawyers.