History is against the situation you describe - even in the days of the Blue Book & certificates detection was required (albeit often just a smoke head either side of the door) as well as automatic release upon manual alarm activation, automatic release upon any fault rendering the system inoperative and release should the system be isolated for maintenance.
So the historical precedent for detection with SC/A doors goes back over 30 years - in theory you could justify that if a building only requires an 'M' system (& you need to be absolutely sure of that in the first place!) then the same applies with the SC/A, but in court or a determination you have got decades of contrary guidance plus various BS guides often used as benchmarks against you.
I'd go for AFD - just because no ones pulled it up before doesn't make it right!
