I would say it depends on the size of your cable box, and how thick your TV is. We were able to mount our AppleTV box behind the TV, but that is a fairly small item.
To remove the TV from the wall mount: Pull the latches down to unlock the TV from the wall mount, then pull the bottom of the TV out from the wall and lift it up and off the wall plate.
I used it for a flatscreen 65 inch but mine doesn’t have a curve so u may want to get one made specifically for curved TVs. I do recommend this brand though