Hey @paul2009,
Wonderful explanation. Glad to hear SS is using Let's Encrypt under the hood and totally understand where the delays occur. Quick question about a better process for transfer:
Would it be possible to add just the CNAME verification record to get the SSL cert to generate and then add the redirection @ CNAME and @ A records? That should be enough for SS to process and can leave the site live on it's old domain until it's clear to move over.
If this functionality doesn't exist, it would be really cool to have that as a feature request.
For those who are struggling with DNS propagation, you can actually speed up the process by requesting the big providers to flush their DNS. For instance, you can request a purge from Google here and you can request a purge from CloudFlare here. I'm sure there are others out there, but I've found that just doing these two typically gets everything I need in a matter of minutes.