How to customize signer RPC for Websockets?

[colinnielsen]

Having some interesting UX on my dApp using WebSocketProvider, or in general: JsonRpcProvider...
Previously, I was using the ethers.providers.web3Provider(metamaskinjected) and using that as both the provider and the signer in my app until I wanted the performance benefits of rpcProvider/websocketProvider.
My app is event-based, so I will receive updated events filtering back into my app before the transaction is 'confirmed' on metamask. It would be really useful for me if I could use the metamask signer details in a websocket provider. Hopefully, this could allow me to do something like:

tx = await MYCONTRACT.connect(signer).MYMETHOD();
const receipt = tx.wait()

Does anyone know how to do this? or will I have to separate any kind of log subscription/transaction awaiting to use the provider? (provider.waitForTransaction)?
Thanks!
Ethers is incredible btw, thanks for all the hard work!