Freestack Responsive is absolutely outstanding for integrating third party code. Personally, I have integrated > 10 third party menu systems into Freestack projects over the years.
Third party menu systems are generally MUCH more powerful than build in theme menu’s as you can have mega-menus, feature content menus and all sorts of widget like stuff going on in them, if thats your thing.
BUT (thats the big but)… without code? Nope. But the integration is generally pretty straightforward and once you have done it a couple of times it gets easier. If you cannot be persuaded to try the integration - by working with some code - then I’ll leave it at that.
If you think maybe you’d like to give it a try then I recommend: Menuzord it’s absolutely brilliant and the developer is extremely responsive and really cares about the product. His Jet menu is outstanding too.