No, that's about right. Keep in mind that it's not that simple, and it never is.
Most front projection is about viewing angle and meeting THX standards at the very least. But, really, it's about comfort in viewing and then everything else starts to become more and more important with resolution NOT being all that high on the list.
Color saturation is more important than resolution.
Contrast is more important than resolution.
Shadow detail is more important than resolution.
Image processing is more important than resolution.
Resolution does matter, but the real jump between 1080p and 4K is the jump in the color space and the typical use of H.265 video encoding.
Most people, from most distances, notice the jump to 4K with a 4K source right away because of the added color depth. Still, with a typical installation size of 10" to 12" of diagonal for each foot of viewing distance, there is no doubt that UHD front projection is where is really all matters most.
