You can do that with a show_if shortcode and extra menu shortcodes.
Lookup the syntax in the Add Ons page.
You would hide the primary menu on all devices using its hide on option.
Then insert both menu in the appropriate insertion area like header HTML area or container top with the proper show_if shortcode like below.
[show_if device='mobile']Extra menu shortcode for the mobile menu[/show_if] [show_if device='desktop']Extra menu shortcode for the desktop menu[/show_if]
I will place a suggestion to weaver to add a mobile primary menu selection in Appearance > menus > Manage location
And you would place th