please realize that random binaries from internet are good for malware spread ...
I agree that auto-installers are a good way to spread malware. Often these installers are recognized by anti-virus software as malicious software.
I plan make an addon install menu in the SE interface. You just drop the file into SpaceEngine/import folder, then SE automatically add it to its folders and scripts. In GUI, you have a menu with list of installed addons with checkboxes to enable/disable them, or even remove. Addon may have a readme/credit file, which will be displayed in the menu when you click on addon.
This is very good solution. So even much better.