Have you read p. 24 in the manual? The FM3, FX3 and FM9 already do this.One thing that was handy for me with my modeler that I had before the FM3 was that it had a 3.5” aux input for plugging in a device so you could play along to something like a song or a backing track. It would be nice if the USB port could be enabled to allow something similar. I don‘t home record, so I don’t have a DAW (other than GarageBand) or an Interface, but that may be wishful thinking allowing the USB to transfer data into the FM3.
Or a LED string ... looks great not only at xmas and doesn't even need voltage conversionThere are a few options out there to convert 5V USB to 9V DC, people with one or two simple pedals next to the FM3 would really benefit from this!