It's cool. You mentioned the need for it to still be switchable, and in my head the removable joy-con were are part of that along with with dockability.
In that case, I love the idea. If it can fit in the regular dock with joysticks still on it (maybe go back to circle pads?) then it'd be perfect. Although the dock price needs to come down. Knowing Nintendo, they'd probably sell a dock adapter or something.