Since UIA issuers have the ability to control all the balances of those who own them, I think it would be possible to allow users to confirm their identity through the BTS client, and receive IOU versions of the assets they currently own on the centralized website. Then, when funds are used on the client, they also reflected on the balances of their centralized server, and vice-versa.
Would this have any benefit for either the exchange, the user, or both?