Cisco style Q in Q tunnels

Hi All

We have a few CRS317 switches with the latest RouterOS which we’re evaluating. I am trying to understand (but not having much luck) how to implement Cisco style Q-in-Q tunnels (ie: customer can send any vlan they want at us and we encapsulate it in our service provider vlan tag) without losing hardware offloading and still be able to process normal vlans as well. Essentially I want to replicate this: https://networklessons.com/switching/802-1q-tunneling-q-q-configuration-example

Can anyone point me in the right direction?

Topic below might get you started:

http://forum.mikrotik.com/t/qinq-vlans-help-needed/120343/1

I’ve looked at this topic.
Using vlan interfaces loses hardware offloading on the CRS platform?