I am not sure I understand the question, but the stall warner should work equally accurately (to the extent of detecting the onset of stall) regardless of aircraft loading, airspeed, etc.
The PA28 can also suffer transient stall warner activations due to gusts
Any plane can, and
AFAIK it's because the gusts (or more likely wind shear) rob you of airspeed and thus can bring the wing close to stall, hopefully only momentarily. The stall warner itself knows nothing about wind, etc. I've done departures where the ASI is showing 100kt and the next moment the stall warner is going off, with the ASI showing 70kt; 30kt of wind shear.