Hello snakecult, I think it is a solo project by digi_b.
I am guessing digi_b use windows with ntfs as the file system for the storage media.
In short, it can not be done.
I looked how to store linux (ext4) files properties on windows (ntfs) and as far as I know it can not be done. I tried transferring an executable .sh from linux to windows and back and the .sh was not executable anymore.
It has something to do with ntfs not being POSIX compliant. I don't remember in details but in short, ntfs (windows) have no way to store linux file properties.
That being said, there are solutions around that.
1) Using a dedicated hdd/ssd with ext4 (or another compatible) file system can be used with WSL 2 (Windows Subsystem for Linux 2) or another program (for exemple Linux Reader) for compatibility.
2) Using a linux virtual machine, copy the files, change the file permissions, compress and then upload from the VM.
3) Maybe using a docker container (which require WSL 2) with a custom script to automate the properties changes, compression and upload.
Seeing the additional requirements I kind of feel bad asking digi_b for that.
Maybe adding a link that explain how to make it executable by the user would be sufficient. I don't know.
P.S.: The comment is a bit long sorry, I did not know how much details to write.
edit: added "by the user" to make the sentence clearer.