I believe the actual aspect ratio of the IMAX cut was 1.81 so using a 1.33 pan and scan (from HBO) wouldn’t be an exact recreation in terms of accuracy either. I think the instinct to keep the original aspect ratio is dead on in this case.
The other option would be to center crop to 1.81. With the admittedly lackluster compositions of the film, such a crop doesn’t actually do that much harm in practice.