I personally contacted AWS support (in the attic of SF Market Street).
It turns out that copying the last 1% of the data when resizing can take from 80 to 90% of the time. In this case, the first 99% of the data was copied in 1 hour. The rest of the resizing took another 10 hours. Unfortunately, neither the documentation, nor the progress indicator, nor the indicators remaining in time reflect this.
Your objection may vary.
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