Samba throughput decreases by 50% on turris omnia if signing is used: Is there a way to accelerate Samba signing/encryption on Omnia Turris with the built in crypto Chip?
Only the very latest versions of samba have support for using aes extensions on intel chips.
I don’t know the answer to your specific question, but generally an encryption chip has not been useful to OpenWrt-based systems (such as TO).
The reason for this (in the case of OpenVPN/OpenSSL) is that the cost of switching to/from users-pace is as high as any savings gained from HW-based crypto.
For you, I might recommend posing your question on the OpenWrt forums.
If he really wants that, I would advise to ask on the samba mailing lists.