@cissou Hey. Unfortunately, I had no luck, or rather no visible changes on extremes of 30-100 MHz when I added this command to "retroarchcustom.cfg", "retro-core-options.cfg", and the "GAME.opt" files. AFAIK, I think you add it to "retro-core-options.cfg" to enable this feature after I examined a Retropie build.

Ah well, thanks for your help, but either I need to dig a little further or the default build of Recalbox doesn't support this experimental feature OOB.