ECS4620-52P Stacking

Hello, everyone!
I have a question. When I activate stacking, the two front uplink ports are automatically assigned to it - 49, 50. I don't have any rear ones. I would like to use only one port each switch for stacking in a line topology, and the other two for connection to the upstream switch. Is that possible?

One more question.
Where can I find the Hardware Installation Guide? The documentation for the web interface says that there is some kind of Hardware Installation Guide, there are more details about the stacking topic.