Dropping the menu switch point feature was necessary. While it may seem that your original version worked, it turned out that it really did not work correctly with all menu configurations, and could not be made to do so. The original addition of that function was in response to some requests, but unfortunately did not get the proper full testing before it was implemented. It was an unavoidable choice.
Adding the exiting new functionality of the SmartMenus was also in response to a large number of requests over time for more menu layout options. Part of the consequence also eliminated the possibility of and easy switchpoint solution.
@scrambler has devised some rather complicated CSS that seems to allow the switch point, but it is still experimental. If there is enough evidence the techniques work, it may be added as an option in the future, but that is not certain.
On the other hand, do note that significant research went into the decision on the design of the Weaver Xtreme mobile menus, and just how they work, and at what point they switch. A significant majority of all websites have been implemented to treat an iPad as a regular desktop layout in both portrait and landscape. Weaver Xtreme’s design followed this majority rule.
Also, significant research has revealed that probably most existing WordPress theme menus do NOT work properly on touch devices. There are generally FOUR different ways different touch devices handle touch events (and this is particularly true for menus). Current Android, Older Android, iOS (Apple), and Windows 8+ touch screens all process touch events differently. Weaver Xtreme has been carefully designed to work on all four kinds of touch processing. A consequence of this is that it is very difficult to have multiple or variable desktop/mobile switch points.
So, if you simply follow what is generally accepted as best web design practice, and treat iPads as desktop layout, Weaver Xtreme works as it should.
At this point, if you feel compelled to have a different treatment of how the mobile menu functions, you will likely need to consider other themes. But do be sure their menus actually work at all on all four types of mobile devices.