Whilst we are on that general topic - I have a vague recollection that inductors used as chokes can suppress high frequency and reduce interference. Is that something that can also be added on the mains side either separately or together with the filter, or is the filter based on a choke anyway.
My reason for asking is that I got very occasional false estops (even though I have a filter fitted) until I used an extension reel on the VFD and plugged it in the other side of the workshop and that sorted it out. Did I create an inductor of sorts ?(cable was mostly still wound on the reel) and if so can a commercial choke be added inside the control box before the filter to dispense with the extension reel?