I am the customer, and can answer these questions...
1. Settings on the gauge: SC ~ 3 o'clock / WL ~ 8 o'clock / WH ~ 1 o'clock
2. 0.8mm jet, 0.5mm restrictor pill
3. Threshold: ~ 10 o'clock
4. At WOT, gauge usually shows3 bars, sometimes flickers to 4
5. Vehicle is 2009 WRX with VF52, stock injectors, Perrin CAI, turbo inlet, AVO TMIC, Perrin EL headers, 3" TBE exhaust - with high flow cats, EBCS