My explanation would be that the 1,43 factor (requirement to land within 60% of LDA)
Perhaps you might like to recheck that sum just once more .... ?
While there will be variations between Contracting States, and between the various historical evolutionary versions of the Design Standards (as with all things) the deal for heavies usually seen is along the lines of ..
(a) planned requirement 1.67
(b) alternate requirement 1.43
A problem is that many AFM landing charts are not factored and you need to add the fat yourself.
Some things to consider -
(a) actual screen location - ie are you high ?
(b) float distance - have you ever seen what the usual performance landing flight tests are like ?
(c) have you ever practised max performance landings ? - a whole different ballgame to line operations
(d) you think you can replicate the AFM raw data on the day ? .. pipe dream. That's one of the reasons for the factor fat.
(e) actual runway surface conditions - ie friction characteristics - especially as you start skating on the upwind touchdown zone deposits with maximum braking ... and, if it's wet/contaminated, you might spoil your whole day, big time.
Keep in mind - always - what your story might be in court after the prang when you skated off the end of the runway and a bunch of folks get hurt or killed. If you had no reasonably feasible alternative, including planning considerations, then you may have a winnable argument for shaving the fat as circumstances required on the day.
If, however, you chose to land on a shorter runway, with another available with lots of length ... rather you be the one in the witness box than me ...