I think they both go together. It might take about 10 minutes to give a good high level explanation of it, including how the S3 syncing works - that the S3 lags slightly behind the caching layer for reads, and that you can still write to S3. 2-way sync. I imagine that S3 would be treated sort of like another client if updates came from S3 and the clients at the same time. It would probably be not so great to write to S3 if you aren't writing to somewhere that's being actively edited, but if you want to write to a dormant area of S3 directly, that's fine.