Setting --single-window mode in snap-EOG

Before I switched to Linux, I used a similar PortableApps technology to do work in Office-compatible apps on a restricted workstation. Therefore, I have hopes that this packaging technology develops.

I wish to set --single-window mode as the default in a snap-installed Eye of Gnome. It runs as expected from the CLI, but I can find no eog.desktop file for a GUI launch. Is there currently no way to do this?