The smaller version s full motion features will let you extend your tv up to 15 inches from the wall while the larger version can extend up to 18 5 inches.
Wall mount for 21 inch studds.
I was thinking of using a 1x6 pine board cut to about 25 in length and mount the tv mounting bracket to the board.
Mounting dream tv wall mount full motion tv bracket for most 42 75 inch tv premium tv mount fits 16 18 24 inch wood stud spacing with articulating arm up to vesa 600x400mm 132 lbs md2298 4 8 out of 5 stars 387.
The whole point of the answer that i posted was about having the 3 4 inch plywood large enough to be 1 larger than the tv bracket and 2 extend across at least two if not three studs 3 the plywood securely screwed into those studs with multiple strong screws at each stud and finally 4 mount the tv bracket to said plywood noting that with proper screws the plywood will be very good at.
For the 32 55 inch version you can mount a tv with wall studs that are up to 16 inches apart while the larger model fits studs that are up to 24 inches apart.
I have already purchase a tv mount designed for mounting a tv to a wall with 16 center stud placement however it turns out the studs are actually 24 apart.
When you have metal studs mounting a tv or hanging a heavy picture on the wall becomes slightly more challenging.
Unlike wood studs where you can simply drive lag bolts or screws straight into the 2 4 studs metal studs are hallow and have thin walls.