A Mustang emissions dyno can easily be converted to YourDyno. However be careful to check the power supply. There have been reports that when connecting the control signal from the Mustang power supply to YourDyno, the YourDyno box blows.
This is only possible if the control signal of the power supply is connected to the mains. Likely the 0V terminal is connected to Neutral.
You must use an isolator in this case. Either a analog to analog isolator or use PWM from YourDyno and connect that to a Optocoupler plus a low pass filter.
Or buy a new YourDyno power supply.