Mr Smith,
FAA D do not separate
IFR and
VFR, that is the same as GAAP!
Where is the data saying there is a safety problem
between IFR and
IFR operating in to and out of GAAP?
Why change something that is not broken!
Edited to add
Why wouldn't we want to have the advantages of GAAP/FAA Class D at all of our non-radar towers?
The advantage to
GA at GAAP is high volume throughput, the only way to achieve high volume throughput is to service less!
I put the question back to you
Why wouldn't we want to retain the additional safety advantages of ICAO D at all of our non-radar regional airports that,
unlike GAAP, service a wide variety of mixed traffic
including high speed, high-capacity RPT aircraft?