Heh. The last 3 words. Nope. ;-)
Sure, it's possible with some effort to create a variety of styles of temporary junk email addresses, but is this really that simple?
Here's a scenario: I can (and do) completely disable all GPS/location activity on the no-data iPhone I'd be using for this. However, if the iOS app talks to the drone before or during the registration/activation process, then I have no way to prevent *any* kind of information, including GPS, from the drone being sent to DJI during that process if the app is online. This would not be surprising at all.
So let's say I physically go to a remote location for a temporary GPS position, then I don't have easy access to WiFi. Or maybe with some effort I could drive somewhere and find an open coffee shop or library WiFi. But for all I know the drone is collecting GPS data all the time whenever it's powered on. That would not be surprising either. Then as soon as it's connected to the app, if the app is online, there goes the accumulated GPS data.
GPS is one of the most important/invasive bits of tracking data of all. Sadly, many people have become numbed to this in recent years. And before people start making paranoia cracks, you need to understand that in the data collection world there's FAR more complex and even bizarre stuff that we *know* is happening, stuff you'd hardly believe, all because of the value of location data.
So if it's possible to register and the only thing they get is a (temp) email address, I have no problem doing that, it's easy. And I'm happy to type in a drone ID, if necessary. But anything that happens on a closed source iOS app, as opposed to a well-understood environment, like an OSS web browser, then all bets are off.
This may have gone further than anyone cares to help with, but it would be great if someone could describe the actual registration process in detail? I mean the order of how things connect and data entered, etc. Maybe once you've done it once it's not easy to know anymore except from distant memories?