I recently had the piston for my 450 Husqvarna treated with both their heat barrier and friction reducing coating. They offer other several processes, very economical-shipping w/ ins. to and from almost equalled their charge for the work. Their friction reducing coating also has the benefit of reducing piston/cylinder clearances if need be-up to .004" thickness is available.
Perhaps some of the serious TW engine modders have also used similar processes.