Update for anyone who finds this post.

I think this was the wrong thermostat for this type of AC. I went out and got an Ecobee to attach to the unit and it’s working great! I did have to call Ecobee to find that I had to change the O/B setting from its default but it’s working like a charm now!

gravity-centered airflow

What do you mean by this? I’ve never heard that term before