I really like CoPay's decentralized multi-sig implementation.   Or at least the idea of it.   I am presently evaluating using it in my business to support a two step payment workflow consisting of:

1) Sally prepares a payment to Bob.
2) Jim reviews the payment and either authorizes or declines.

( This mirrors existing online banking functionality. )

In this scenario, Sally works for Jim, and Jim has ultimate responsibility for the funds.

Ok, this seems simple enough at first:  It could be a 2 of 2 or 2 of 3 wallet, for example.  ( with the 3rd key being an offline backup, held by Jim. )

But now what happens when Sally decides to leave the company and Ellen is hired to replace her?

Ideally Jim would be able to revoke Sally's key and issue a new key for Ellen.

But as far as I know, there is no provision for key revocation in bitcoin.  right?

Ok, so maybe we just ignore Sally's key and will never authorize a transaction initiated by Sally.

( and I see no technical reason why Sally could not be removed from the wallet for future transactions. )

But we still need a new key for Ellen.   And our wallet was created as a fixed 2 of 3.

So is there a way to add new participants/keys to a copay wallet?

Or more generally, I would like to know if the CoPay team has thought about this practical matter, and how they recommend for users to deal with key management when personnel change.

If I'm not mistaken, the only possibility at present is to create a new wallet for Jim and Ellen, then transfer the funds to it.   But that is gross for various reasons, not least because the transaction history gets spread across wallets.