[kartickv]

Is it hard to tune the gyro because its accuracy is too low, or because it's accurate to begin with but degrades over the course of the long exposure?

Is a pure software solution even reliable enough under these conditions? Slowness can be worked around by doing it in the background, and you get a notification when it's complete. Some people would be okay if that's the only way to get photos they wouldn't otherwise be able to get, short of buying an SLR.