I don’t have other recommendations, AWS is actually a decent choice because it is widely used, which increases the likelihood to see features being implemented and support on problems you might encounter
I have updated the dev-elise branch to fix the error you were seeing, feel free to sync again and see whether the original error disappeared
Also, I did find that S3 buckets do seem to have limits on the number of requests they can handle, but the numbers are quite high:
Your applications can easily achieve thousands of transactions per second in request performance when uploading and retrieving storage from Amazon S3. Amazon S3 automatically scales to high request rates. For example, your application can achieve at least 3,500 PUT/COPY/POST/DELETE or 5,500 GET/HEAD requests per second per prefix in a bucket. There are no limits to the number of prefixes in a bucket. You can increase your read or write performance by parallelizing reads. For example, if you create 10 prefixes in an Amazon S3 bucket to parallelize reads, you could scale your read performance to 55,000 read requests per second.
So I’m not sure how it could have happened, but if you’re the only one experiencing this problem and it happens across browsers, chances are that your IP has been flagged on aws, or something like that…