My previous post was meant to say that it is possible, not that it was easy to achieve.
I believe that the H in route print is - in the best case - a “flag” meaning:
IF the nat (src-nat or masquerade) is correctly set AND IF Vlans are properly configured AND IF firewall fast forward is correct AND IF three of the seven (or eight) planets are correctly aligned, THEN M;AYBE this route will be hardware offloaded.
More seriously RouterOS (for the good and for the bad) has settings scattered all around the configuration, particularly when dealing with “niche” settings like hardware offload, a teeny-tiny mistake in a seemingly unrelated area might make the difference between success and failure.
I would advice you to post your FULL (anonymized) configuration, along these instructions:
http://forum.mikrotik.com/t/forum-rules/173010/1
so that some of the more expert members can hopefully spot the setting(s) that need to be changed.