Amazon S3 Adjustable Chunk Size
The Amazon S3 backup script hard codes chunck size to 20MB. This causes excessive PUT transactions that can make small daily backups exceed free tier and raise the costs of S3 backups in general.
This combined with the other feature request for retry chunck instead of entire file would make S3 backups more cost efficient.
Please include a WHM Backup advanced option to adjust upload_chunk_size.