Whether this is NEC3 or NEC4 the general principle remains the same, in that when secondary option X1 has been chosen, the assessed value of a compensation event is adjusted to the base date and a price adjustment for inflation calculation is applied to the ‘CE amount’ following inclusion in a payment assessment.
If compensation events have been assessed at ‘current prices’ then they should not be subject to an inflationary adjustment and so excluded from the calculation under X1.