the most common type of IMAX nowadays is "just" running two 4k laser digital projectors, overlapping eachother so you get double the pixel density, at a much better contrast, and at 60fps.

Unfortunatly, that's still less than half the resolution of the "old" 70mm horizontal film projector. But it gets rid of the absurd arc-lamp they have in the film projectors, which would be the envy of ww2 searchlight operators.