Is it really an edge case these days? A user’s very first sync is likely to be the largest one, to seed all the data into the could. That could easily be thousands of files.

Installing on a desktop, laptop, and mobile device would bring 3 clients into the mix right away.

So the user’s first use is likely to be one of the more complex operations, and the one they absolutely needs to work, as a failure here will lead to the user looking elsewhere for a solution.