Not having a go at FSOs. By all means, bring them back.
I'm merely pointing out that the people who think FSUs knew of all traffic were blissfully ignorant of the reality.
Many aerodromes OCTA were not in AFIZs (but I'm guessing you knew that).
And I'll stand corrected, but I'm confident that there were exemptions for NORADO aircraft - e.g. gliders and aircraft without engine driven power sources - to operate in AFIZs.