The SSH Communications "transfer client" (at https://www.ssh.com/) lets me change the permissions on a global basis for all uploads, both by files and by directories. Perhaps we should be able to do that in WinSCP?
Please try to specify in detail, what you ask me for. I do not understand.
If you try the SSH client (at https://www.ssh.com/) you will see it allows me to specify upload DEFAULT file and directory permissions. That means that I can force other than "600" permissions, a problem for me and perhaps others when uploading.