I have exactly the same problem with a DJI Mini 3 Pro. I have thought about looking for an expert in soldering circuits or something similar, to try to solder an extension to the headless screw and try to turn it until it is removed, but I see it as extremely difficult given the very small size of the screw, the solder point can easily spill towards the driveshaft and make it worse. I am about to undertake this search for someone who is an expert in this. If you have any other solution, I will greatly appreciate it. This is the broken screw, just that little black point in the center of the driver shaft. And these are some pics of the screw in good condition.