is very important to know on which version or routeros are your devices
I think qos-hw-offloading is a new feature, so in ros 7.16 has been polished and also provide graphical interface on winbox to easily configure and monitor
remember to do your due diligence before making changes on your devices, always do backup and export of your config to your PC
i have seen some times after changing qos hw settings a reboot is needed for full stability
here is the info related on documentation
https://help.mikrotik.com/docs/display/ROS/Quality+of+Service
official topic related
http://forum.mikrotik.com/t/qos-hardware-offloading-qos-hw/166573/1