i think currently there is no solution for that as stated on another related topic
http://forum.mikrotik.com/t/crs-switch-rule-rate/164212/1
Maybe in some future when Hardware QoS be fully operative, currently appears to be a work in progress, as always there is no deadline defined for this development to be released
QoS Hardware Offloading (QoS-HW) official topic
http://forum.mikrotik.com/t/qos-hardware-offloading-qos-hw/166573/1
official documentation
https://help.mikrotik.com/docs/pages/viewpage.action?pageId=189497483