You might want to add the bit from the blog about worst-case attach times to your research. From my own experience (though it was years ago), sometimes an EBS volume would fail and simply never return. Definitely won't be acceptable for some use cases
Yes, we've been testing volume attachments every 5m since start of the year, and have experienced 100-150 attachment failures per volume type in that time frame during multiple events (most recently last week):
Another interesting bit, is last March AWS changed something in the control plane which both triggered a multi-day LSE, and ultimately increased attachment times from 2-3s to 10-20s (also visible in the graphs).
