Thank you, this worked!
For others’ reference so a separate install file isn’t required, if you feel comfortable modifying the files in the plugin you can resolve that way. The fix is manually updating the $part_data in class-destination-s3.php on or about line 984 (obviously this may change in future versions) so that the minimum part size is 25mb instead of 5mb.
Thank you for the link. Unfortunately, it results in a 404 Not Found Error.
