With regards stretcher fits........ whilst many of us cursed stuffing the strops into / dragging them out of stowage pre / post depth maintenance, and often wondered if the side stanchions really needed that many brackets it all became obvious come TACEVAL. Most had been on enough routes to know what the cowhorns were for, and rigged the static frame for families day to show people the various fits that Albert could achieve. This included a centre stanchion with stretcher so we knew a little bit!
Sods law dictated the frame chosen was in a 13C or 3A, part of the fun for the umpires no doubt. I forget what numeric role config the fit was but out would come the 5E for the NCO to study (remember those days when an NCO had to supervise role fits). So rambling on ...........re-role to clear floor, keeping the centre stanchions in and move the brackets to correct position. Slacken seat backs, install cowhorns and start dragging out the strops (colour co-ordinated and correctly positioned of course).
From my experience this was usually an hour or so into the role CX and the umpire would stand in and either halt the task, or as in one case inform us that the LOX plant (next door) had been hit & we were to act as casualties. Not sure we would survive such a blast but never mind.........point is we never achieved much of the re-role so can`t confirm what problems we would face further down the line, just to add after the first exercise we learnt well and just got one strop out at a time until we were stopped.