I used a small hiking compass to look for magnetic fields before mounting the sensor case. I mounted it in the forward nose area.
To set up the Butterfly unit you fly figure 8's. This gives a score. I was able to get 8 out of 10.
I needed a longer cable from the sensor unit to the display. I was able to find one online and didn't need to get it from Air Avonics.
There are many parameters that can be changed. It seemed to look like a development project adjusting lag time, T.E. compensation etc. I've tried different ways to get static pressure on the plane also. My hope was for a vario that shows lift and not energy change. Meaning not showing stick thermals. I've not been able to achieve that. Not sure such an instrument exist yet.