G’Day @Jason_Tulloch,
The engineering team has been able to repro uploading images slowly using the latest aws-sdk s3.
The time of just uploading image depends on the image size pretty likely in a linear way. For a small image with size 3k, time spent is ~500ms; for a medium image with size 117k, time spent is ~3.5s; for a large image with size 447k, time spent is ~12s.
I will update you once I have more info available. Meanwhile, would you be ok to use small images, or is it not a workable solution at all?
Best,
Henna