HOTAS isn't meant to replace cockpit switches. They're meant to be used for essential functions just like with real aircraft. I've only assigned commands found on the real HOTAS of the KA-50, so I have heaps of space left on my X-52. I don't plan on adding anything more (beyond push-to-talk) though, as that's what the clickable cockpit (and keyboard) is for.
Mind you my Falcon AF profile is pretty nuts, using all 3 modes and pinkies. I guess there needs to be a compromise to cover switches that need to be accessed quicker than using a mouse/keyboard.