Thanks to your feedback, I made a few small changes under the hood.
If a folder exceeds the Android file system EXT4 and POSIX standard, more then 255 characters, which happened by downloading the complete google drive folder, instead of a cryptic error message about permissions, it will now clearly state what the issue is and to rename the affected folder to a shorter name.
Also on the homescreen I arranged the supported file types in uncompressed and compressed. This make it easier for people new to GS to select the format they want and know what to expect. SPZ has a hugh reduction in file size but zooming in you will loose details and see more splats.
The update should be available, Google tracks it as update 7.
Thanks for your testing and support,
Pete