Recently we have changed the way node id is generated in devnet. In summary: in mainnet, it’s not possible for multiple nodes using the same wallet because node id will only depend on your public key, and it’s not possible for multiple nodes to run with same id (otherwise you will end up with only one copy of mining reward regardless of how many nodes you run). Essentially we are using our blockchain as a PKI (public key infrastructure) and this will be a way more safe method and it prevents man in the middle attack from root.
BeneficiaryAddress will be the only option for multiple nodes to mine to the same wallet. So if you are running multiple nodes with same wallet in testnet now, I’d recommend you to try out BeneficiaryAddress now just to get started earlier
Using BeneficiaryAddress is as easy as putting a line in your config.json
"BeneficiaryAddress": "your nkn wallet address"
In case you are not familiar with json: config.json should be a valid json file, which means the last item shouldn’t ends with a comma, while the rest should.