Ok, so here is the situation, and not sure you’ll be able to help but still wanted to ask.

So the theme has set a mobile menu but I really don’t like it, so I’m using a plugin called Responsive Menu which works great for creating responsive menus on all the mobile devices. And being a little clever, I just created a completely new menu in the Appearance>>Menu area and just didn’t assign it a location. That menu is working perfectly with the Responsive Menu plugin. Because of this setup, I have the menu ID number for the menu, but don’t have a theme_location as this is separate from the theme.

Is it possible to to use a menu ID instead of theme_location?
Thanks