Sorry... I had overseen that whole topic as only the last comment would refer to SSHFS...
`use_atomic_file_saving` does indeed work for saving the file. But since it doesn't keep the original file permissions it brings other issues...
Too bad... Gimp (a Gtk software as well) does it right so it seems Gtk isn't necessarily doomed đ
I wish I could use it at work on my Win10 station as I love it so much on my home's Linux đ