When your foot is on both the board is on, but if your foot comes off either side a little it will cut off instead of reading half.
Direct from Fungineers,
James awesome build!
The little focer has a different pinout than our stompies. Our stompies are adc1 - 3.3v - adc2 and the focer is 3.3v - adc2 - adc2.
So you would have to carefully take out one pin from the jst connector (the middle) and swap it with the first pin on the jst.