Thinking more about this, if Deus changed his code to throw off pursuit, a Resonance Realms search wouldn't find his old code, would it? It would find the new code.
Unless every version of everything that's ever been on the Matrix could be found there. In which case that opens up a whole new can of worms. Perhaps using Morgan's old code to 'heal' Mageara? Having the Deus of the Arcology chat with Deus in his current form (which I'll say is Pulsar until we have evidence otherwise)? Mirage and the e-ghost of Captain Chaos showing up on Jackpoint?