Landing distance calculations is not an exact science (too many variables) so there is a big scatter in achieved results. Sometime you may wish you had that extra 50 m of runway in front of you rather than behind you.
I wholeheartedly disagree.
One thing is the dispatch criteria, where the distance is factored with 1.67 (dry), 1.92 (wet) or for contaminated highest of 1.15 x actual contaminated of wet, which ever is higher. A 50 meter margin
may be ok, since you already have a margin in the calculations (but be careful with wet contaminants, as they will generally be limited by 1.15 and thus have the lowest margin).
If your
inflight calculations (ACTUAL unfactored landing distance) are so tight, that you believe you need to do "tricks" to obtain an extra 50 meter, and if you did a calculation for dispatch and it was ok, the only possible explanation that your inflight calculations may show such a discrepancy, is that during the flight the runway unexpectedly became contaminated/wet (and was not forecasted for you to consider during dispatch). In that case I would either recommend to hold for the runway to be cleared or a diversion. If your company choses to operate into such a short runway, for the type you are flying, I am sure they also accepted the higher risk of diversions in such cases.