Since no one responded yet. I will give you my thought about TR for your seating arrangement. I do not think that any type seating affect the TR that much.
But your type of floor do. Folks with a hardwood floor have great results for TR. But if built over a concrete floor, the TR is pretty well not existing.
When leaving in a place with hardwood floor, my single PB12 Plus/2 was very much present.
Then move to my new house, with the Theater with a concrete floor and no TR at all. Adding a second PB12 Plus/2 did not help at all.
So did moving to two PB13, for TR. And use the first type of seating arrangement for extra info.
Darth