Neale - Thank you, very interesting thread. I hope you will post your results please. I have been down this road on a similar router with moderate success using carbide+coated cutters. I did find a definite advantage adding just a smear of the blue EP metal working lubricant, with a finger, to the projected toolpath. So minimal mess and it also kept some of the chips on the metal surface.
Your VFD setting results would be particularly welcome as have to admit a bit windy of touching my working settings.