But I see no reason why the person should downgrade his wallet as it will take much time, although it is an option that can be used, but why the person do not just use the latest version, click on view -> console and type in the first command above which will bring up seed phrase to generate legacy address and import it on the latest version of Electrum wallet directly, it is as easy as that.
It doesn't really take any time at all... and you don't need to downgrade anything.
Simply download
the portable version of Electrum 4.0.9 and run it in it's own folder somewhere. It won't affect your current installed/standalone version or existing wallet files... and you'll be able to generate all the "legacy" seeds you like using the GUI without having to worry about renaming/moving wallet files, or messing about with the console commands.
Additionally, any wallet files made with 4.0.9 portable can be easily copied over to (or opened with) your 4.1.5 (or later) version and "upgraded" without issue.