...noticed choppy playback on my TV. Upon closer inspection, the FPS appears to be changing with each frame.
What file type and codec did you export for viewing on your TV?
What are you using to play back on the TV, and what is telling you the fps is changing?
Does the file play smoothly if re-imported into Premiere?
What settings do I need for a constant 24fps with a high bitrate ?
Whatever fps setting you use on export should not vary or be altered.