ARFOR
There are no “additional safety advantages” of ICAO Class D over FAA Class D. If there were, the United States with 350 Class D airports would change to this, and end up with a higher level of safety.
The real difference between our Class D and the FAA Class D is the simple clearance request for entering the zone and the removal of the useless VFR departure call.
Under ICAO and under FAA Class D, IFR are given traffic on VFR.
By having simple, standardised procedures for all of our non-radar towers, we will get higher compliance and therefore, I believe, higher safety levels.
Even if we don’t go to higher safety levels, surely making something simpler and standardised is better.