or had known that the stopping margins calculated by the on board performance computer for the 737-700 already assumed credit for the use of thrust reversers
- it seems pretty clear to me and to the NTSB - 'other crews' knew this, this crew is thought (either not to have planned for it or) not to have known it according to the report.
"Boeing's recommended airplane performance data"
- not sure what you mean by that. As far as we are concerned, these figures are in the Boeing QRP.