USB is supported in Allard's sketch without hardware modification, but it is a good idea to remove C91 and C92 as they are unnecessary when using a
Raduino and only serve to reduce sensitivity when in USB mode. Also Allard's sketch allows you to set the VFO drive level for USB, independent of
the value used for LSB. Technically USB isn't needed for BPSK (it will still decode fine) but it is necessary if you want the dial frequency to be correct.
Most other Soundcard Modes will require USB. The PTT sense mod is also useful as it will allow the Raduino to lock the VFO frequency during transmit
so that there is no inadvertent change ... likely a good feature for Digimodes.