Danny, the devil as ever is in the detail, and we are always indebted to you for your attention to it. It is the 'reverse engineering' that you apply to the apparent policy changes of hours allocation in your above post for example that gives us a glimpse of the higher direction of this massive training programme that fed the allied war machine.
Thank you for your explanation of the SFTS, something that predated the programme it would seem. Attention now moves towards our trainees home-coming, for it seems there is a further flying training course to attend, AFS. Why was this done in the crowded and dangerous skies of wartime UK? Was that part of the 'advanced' experience deemed necessary, or was it merely familiarisation with European rather than Continental US (or wherever) climate and weather? Of course, if one's ultimate posting was to the ME or FE such experience might be seen as somewhat superfluous, but that is being a bit too pedantic I suspect.
Operational training at the OTUs (and heavy conversion units, if required) obviously then tuned one into the final type and role one was destined for, but the many different schools/ units that spanned the journey from Tiger Moth to Stirling (say) made for a surprisingly long and varied learning experience up to that first (and sadly far too often last) operational sortie.