I share the sentiments above regarding 'procedural' control. Just one discrepancy in HBs statement that I would like to highlight.
An aircraft only requires permission to enter an ATZ if that ATZ provides an Air Traffic Control Service. In the case of FISOs or A/G services the only requirement is for the pilot to obtain sufficient information such that flight through the ATZ can be safely achieved. This obviously only applies to ATZ outside CAS.
I do not have the reference to hand but it's somewhere in the ANO!!