For a full 90 swing, a single arm mount might be better.
Peerless pla50 will do it. That's a 55 in the picture.
The Chief ts325? Just put a 46 on one today, did not try 90, do not think so?
At least not as easily as the pla50. Maybe I did not try hard enough?
Both mounts are flexible on mounting location left/right.
Both weigh more than the TV.
The Chief has more adjustments and is WAY thinner, the Peerless will add about 6" depth!