Interesting topic. In addition to all your assumptions, the line up distance used to offset Nose Wheel and MLG are important. Perhaps educating the end user too.
For dry assumptions, yes, the reverses are not considered, however, if your stop Margin shows 2m, that’s assuming the stopping action took place at V1 plus 2 sec reaction time. Decelerating is now with 50% of the referrers that you have anyway. (Practically speaking). Therefore the Stop margin is brought quite a way forward and will always look different from the computation versus the real thing. That’s what and how we try to educate our guys.
Also someone has mentioned before, the assumptions are based on an avaerge call to stop, cold and work brakes.
Wind components assumed for the calculation at this of 50 or 150% depending if it’s head or tail. Again very conservatively put, additional margins are built into the assumptions.
Your EFB administrator can set up the output of the performance module to display a range of Flex temps and or TOGA. However, you’re now not using the optimisation process ‘as advertised’