Houston Climate Zone 2: Hybrid vented & conditioned attic or insulate entire roofline? – GreenBuildingAdvisor

We are building a 1½-story home in Houston (Climate Zone 2) and are trying to achieve a high-performance building enclosure without using spray foam.

Our current design is to insulate at the roofline using R-38 Rockwool between the rafters, with vapor-diffusion ports at the roof ridges for moisture control. The HVAC equipment, humidifier, and ductwork will be located within conditioned space.

One concern with this approach is that, because of the roof configuration, multiple roof masses, and interior wall divisions, there will be fairly large attic/roof areas that will essentially become conditioned space but will have little or no access after construction.

Would it make more sense to use the R-38 Rockwool/vapor-diffusion-port approach only for the main roof mass, where we want the attic to be conditioned, and construct the other inaccessible roof masses as traditional vented attics with approximately R-60 blown cellulose at the ceiling/floor level?

In the attached images, the blue-highlighted areas represent the roof sections I am considering bringing inside the conditioned enclosure, while the red areas would remain vented.

Alternatively, would it be better building-science practice to keep the entire roof assembly consistent and insulate all of the roof rafters with R-38 Rockwool and vapor-diffusion ports, even though this would be considerably more expensive and some of those attic areas would never be accessible?

Is a hybrid conditioned/vented roof approach practical and recommended for a house with multiple roof masses like this, or would you recommend keeping the entire roof under one conditioned roof assembly?

Any suggestions or experience with similar assemblies in a hot-humid climate would be greatly appreciated.