Some of these quirks are just extra headers. Others are changes to hashing, or additional checksums. Cloudfront adds a custom signer for making cookies. S3's is basically a rewrite of the client, 1000+ extra lines.
Every service in this folder should be triaged for whether the quirk is blocking, how important it is, if the service needs to be marked "broken" until the quirk is implemented, etc.
The Glacier module didn't actually work because of a Glacier header quirk which aws-sdk-js handles directly. There is a whole directory of these: https://github.com/aws/aws-sdk-js/tree/master/lib/services
Some of these quirks are just extra headers. Others are changes to hashing, or additional checksums. Cloudfront adds a custom signer for making cookies. S3's is basically a rewrite of the client, 1000+ extra lines.
Every service in this folder should be triaged for whether the quirk is blocking, how important it is, if the service needs to be marked "broken" until the quirk is implemented, etc.