Reload game when modlist has changed - Option not available on Steam

[RicRider]

When I change my modlist on the DRM free version from the Ludeon site it has an option to restart 'Later' in red.

On Steam I can't see this option, it automatically restarts the game.

This is an issue because I'm trying to load a modlist from a save, but the save is missing a mod (Harmony). I have Harmony subscribed on Steam and I don't want to have to manually check all the mods in this test game I'm running. Does anyone know how to configure the Steam version to NOT automatically restart when I change mods, so I can just enable the Harmony mod in the right place and THEN restart once the main modlist has been loaded?