w.r.t. the 1deg flextemp difference:
From my observations:
Sometimes the RTOW charts or FOVE take-off performance module will come up with a flex of Tmax flex. (ISA+60 or ISA+53 for CFM, IAE respectively). This is ofcourse corrected for elevation.......
1. It can be sometimes that there is a totally acceptable discrepancy between the elevation used by the RTOW chart/FOVE and the actual elevation when FLEX thrust is applied.
2. Also the FADEC will not round up Tmax flex to the closest whole degree I would think, but rather always round down to the lowest whole degree to NEVER exceed the Tmax flex limitation. The RTOW charts/FOVE will correct Tmax flex for elevation ofcourse but might round up at times, especially when elevation is just a few feet of a whole round 1000 ft figure (e.g. 2002 ft).
Just my thoughts......