CMOS vs. CCD shouldn't matter, nor should "estimated" uncertainty of individual astrometric positions.
What should matter is leaving out observations with bad residuals -- something that the MPC doesn't do much -- and not publishing perturbed orbits for comets with short arcs.? The MPC should only be publishing parabolic orbits for new comets that have highly elliptical orbits -- and certainly not hyperbolic solutions with 1- or 2-week arcs.