One more addition, as I've just seen the addendum of the review mentions that there is almost nothing in the user manual: the Manuals in the Mikrotik world only describe HW specific quirks. You have to go to: help.mikrotik.com Then study it for a few hours, days...

Here is the description for passthrough: https://help.mikrotik.com/docs/display/ROS/Ethernet#:~:text=...