That's an interesting thought. It should be possible, because a spark address is simply a public key. It won't be possible out of the box with breez sdk in the current state, because of the way the keys are derived from a mnemonic. But it's possible theoretically for sure!

With the Breez SDK we just shipped lightning addresses out-of-the-box, without developers needing to host anything. It doesn't have nostr support yet though!