I think the only way to future-proof 24 fps content is to render it as 120fps, but repeat every frame 5 times. 5 * 24 = 120fps.

I don't think TVs can frame smooth that. It should display as intended.

It was probably a Technology Connections video or something but I learned that film projectors actually flash each frame 3 times before progressing to the next so the light is flickering 72 times a second, while the image is only changing 24 fps.