Hey @T1m0thy! Thanks for bringing this up, and @jg80 thanks for the assist! I can see the same results with fileDropzone.value[i] vs fileDropzone.value[i].base64Data. This documentation was made before we put all the file object information in the value array, as some of the information was stored in component.files previously and the value was only the base64Data. I'll have the docs team update!
On the S3 uploader component itself, I'm not having that issue. But it's likely due to file types. This component is ultimately much less configurable (as you noted), which is one of the reasons that it is being deprecated. We do recommend using any of the file input components and an S3 resource to upload files.
Let me know if you have any other questions!