This is great work and a great post. I made sure it was referenced in a Mapbox blog post that's been scheduled to go out today. I didn't see the Alibaba support coming, that's going to be a big deal for some users. Me, I'm eager to exercise the HTTP/2 feature.
Users with large storage needs and tight budgets might want to look
into B2 from Backblaze. It's significantly cheaper
than S3. The structure (buckets and file) is similar to S3 as is
the API, so implementing access in GDAL is probably pretty
straightforward from the S3 implementation. I don't use cloud
storage for geo-data, so I won't be pursuing this route, but I do
use Backblaze for backup and have been extremely satisfied.
Full disclosure: My connection to Backblaze is pretty minor - one of
the founders is a friend of a friend (ie, almost no connection at