My operational experience is limited to Australia. Here, the 1.67/1.92 are required for normal operations. The relevant CAO (Civil Aviation Order) 20.7.1B (for larger aircraft) requires the LDR be equal or less than the LDA given the actual landing weight (and other pertinent factors). For an emergency situation, then, one does the best one can.
I'd be very surprised if this thinking doesn't apply world wide.