What is known. There were a huge number of people who just got notices. But compare it to the number of Amazon users, and it lowers the percentage of getting one. As for temp bans or temp blocked accounts, yes, that too happened, but it’s suspected that those were doing more than just downloading on their Amazon accounts.
And from what those who did get a block or ban said, contact Amazon, and most got their accounts back.
There is and always will be a risk. Others reported miscellaneous providers acting up at one time or another.
StreamFab even said that is why so many are limited to 100 downloads a day.
It is still, to this day, a bit shocking that they increased the downloads for Amazon to 200.
It could just show stupidity or faith in their fixes to stop Amazon from knowing you are using streamfab as a downloader on Amazon.
With software like this, each user takes their own risk.
When you think about how long Streamfab itself has been around in the whole picture, the Amazon notices, I think, were the biggest concern about using streamfab.
If you want to play it safe, use a recording software like Playon or RecordFab.