The test data normally is analysed as three separate segments
(a) steady approach
(b) flare
(c) landing roll.
Final data will be figured from 50ft to a stop with the tightest flare the OEM can get away with ...
Keep in mind that the
(a) TPs will discard untidy test card points
(b) the aerodynamicists doing the data reduction will get rid of some more
(c) the OEM finally negotiates an outcome with the Regulator
Anyone who thinks that the line pilot can replicate the published TP raw data is a comedian. Occasionally one might come close but, on most occasions, the line effort will be found wanting.
Hence we have a landing distance factor to provide a reasonable amount of fat. Historically the factors used appear to be reasonable as we don't have aeroplanes running off the end day in, day out.
If we find ourselves landing on a runway the distance of which is longer than the factored distance required ?
Can we go for a nicer touch down ? Of course.
Should we do so ? Generally not. Reasons are consistency and the (often) significant distance which can be squandered trying for a nice touch down.
14000 ft available in a B737 ? maybe one relaxes.
6000 ft ? bit silly to relax, I suggest.