Hi Jeff,
Thank you very much for your feedback.
We do not handle the duplicate filenames today for the reason that we do not support multiple folder uploads (to keep compatibility with older browsers). Just removing file duplicates check will not help us much because uploading true duplicates files would trigger another set of issues.
Congratulation for having found a workaround. There is a similar thread discussing this issue here: https://community.pix4d.com/t/6553-Cloud-platform-image-uploads-same-name-error
We hope to find the time to implement a better algorithm to disambiguate real duplicates from different files with the same name.
Thanks again for your feedback,
Olivier