Hi, you might want to check out how automatic registration is done in our AWS and IBM Bluemix examples. There’s also some Azure docs, that we are happy to get feedback on https://docs.resin.io/integrations/azure/
The general method is either a) having an external service that can communicate both with your 3rd party provider and resin, and when a new device shows up on resin, it sets it up with the 3rd party service (the AWS example); b) devices self-register onto the 3rd party platform (the Bluemix example).
I guess what you mean by disabling auto-registration is that if you manually register a device, then you have to manually generate the config.json
(also with the resin-cli), and set your device up with that config, then the device will boot up and start with that info (and since it has “registration info”, it won’t try to re-register). Does this make sense? I think that would be possible to match your workflow.