When connecting the Spooky2-XM to the Scalar device and running a program from the software , is it necessary to choose Scalar preset to make program more effective?

The Spooky2 Scalar Input needs the correct Voltage to work.

If your XM generator produce too low Voltages, the Input will be ignored. So there will be NO effect over the frequencies at all.

If your XM generator produce too high Voltages, the Input may be damaged. (Do not know if the input is protected and how. The circuit diagram is not public domain.)

So the answer is YES.

It is necessary to choose the scalar in the settings.

For more details, please check the link:
https://www.spooky2.com/forums/viewtopic.php?f=6&t=9953