Why PE test 1 doesn't check PMCR_EL0 bits[15:0]?

[sunnywang-arm]

PMCR_EL0 is NOT mentioned in BSA spec Appendix A Table 18 (Permitted architectural differences). Why do we need to use MASK_PMCR to allow the difference in PMCR_EL0? https://github.com/ARM-software/bsa-acs/blob/8d2382ad2be86ee2598dc69703e11c9315c3cf2b/test_pool/pe/operating_system/test_os_c001.c#L85