Microstrip filter manufacturing tolerances in cheap fabrication.

Recently i found out that such problem still exists. I searched this board and found this old thread: https://www.edaboard.com/thread49614.html , that suggests to and also Any news in this area? I read about ring resonators are good for overetching, because only it's inner and outer radius is affected, but mean radius remains at designed frequency lambda. The other way is to make filter for a little higher frequency and always tune it by adding high dielectric material on top, or some conductive paint to make lambda a little longer. If any cheap proccess available to make tighten tolerances, i would be happy to hear.