Yes,
The torch cable itself is like one giant broadcasting antenna. RF is going everywhere. This is what has to be grounded on large CNC cutters that are 100+ amps. Almost all over 100 amp plasma systems are HF start. The torch cables themselves have to be shielded from radiating the energy. This is the first and foremost part of shielding. Also the unit should be set up to capture any radiating energy. Look up Faraday cage. Capturing HF/RF emissions at their source is easier than trying to block them once they are out. Mike and Ray can comment more, but this is what my conversations have gone with a major CNC table company technical department.