QA_DT_HASH doesn't work like the other QA ignoring flags in that it doesn't support QA_DT_HASH_x86, QA_DT_HASH_amd64 when it really should.
QA_PRESTRIPPED_${ARCH} also isn't supported.
Fixed in r14114.
What version of Portage is that going to be so I can test?
This is fixed in 2.2_rc39.
This is fixed in 2.1.7.