Service cavities – GreenBuildingAdvisor

I asked this question in a comment on another article but maybe that’s not the best place to ask. We have our new house built to the point where we have the cavity insulation and Intello up on the inside of the exterior walls (no interior walls built yet). We’re planning on installing 2x4s on edge for the service cavities on the walls and ceiling so we have enough room for various recessed lights in the ceiling and window shade pockets and receptacles in the walls. In one wall we need to use 2x6s on edge to fit the shade pockets. I have seen a lot of people attach the strapping horizontally on the walls so the electrician doesn’t need to drill holes but we were thinking vertically makes more structural sense just so the 2x4s and 2x6s aren’t sort of cantilevered out. Also, my husband is the electrician and he says the holes help to support the wire anyway. Is there a downside to placing them vertically? We will have continuous exterior insulation so that will help with the thermal bridging of the studs. And should we just use long screws and attach them to the existing studs? Do we need to build the service cavity walls with bottom and top plates and then attach them to the structural walls? And do we even need them to be continuous from the bottom plate to the top plate? Trying to figure out what’s important. I assume the key is making it easy enough to hang the drywall in the end, right? Thanks for your help!