We often quote the phrase "more applicable data" as in B31.3 para. 319.3.6:
In the absence of more directly applicable data, the flexibility factor, k, and stress intensification factor, i, shown in Appendix D shall be used for flexibility calculations described in para. 319.4.

I do not have the EN code in front of me now but if the EN code has similar references, then, as more applicable, B31J should be applied.