The one I have now is just a flat mount (no extended arm) similar to this...
https://www.ebay.com/i/371351090786?...103d06ffe3ac42
It's about 5"x5" and I think I paid $30 ~ $40 for it.
You need to mount the wall plate low enough so there is enough room between the wall plate and ceiling to lift the television above the bracket and slide the slots on the portion of the bracket attached to the television into the slots on the wall plate. I think the stick serves as a general guide to location with some latitude to go up and down to position the wall plate to accommodate mounting and removing the television from the wall plate for storage.
I've mounted three different wall brackets using 1" screws and never compromised anything on the opposite side of the bracket (interior or exterior walls). The brackets have held the television securely (19" flat screen) during the normal rocking and rolling of the trailer when camping but I wouldn't trust them on the road so I remove the television for traveling.