Hi,
I work for an audio manufacturer and from an acoustic perspective, it would make the most sense to mount the TV along with the soundbar or center (what type the system will be is also interesting, in case I haven’t overlooked it...) centrally on the short wall. A three-seat sofa as a room divider positioned roughly in the middle of the room and to keep it from being too close to the dining table, rotate it by 90°. Possible rear speakers, if direct-radiating, could then be hung on the other side of the room in the corners near the dining table and would provide a nice multi-channel stereo sound distribution throughout the room during parties. In home theater mode, the distance and resulting diffuse sound characteristic create a nice room ambiance similar to dipoles. Front left/right speakers should definitely not be too close to the rear or side wall!
I wouldn’t choose the angled orientation, but I certainly have different priorities there.
Best regards
Tolentino