Function eval_analog_instance_chopped 

pub fn eval_analog_instance_chopped(
    schedule: &GainSchedule,
    target: &AnalogTarget,
    inst: &InstanceSample,
    model: &NonIdealityModel,
    inputs: &[f64],
    frame_seed: u64,
) -> f64

Evaluate one die CHOPPED: two frames — normal and polarity-swapped (each frozen offset enters negated) — with FRESH noise per frame (drawn from frame_seed), averaged by the digital side. The frozen offsets cancel EXACTLY; what survives is a deterministic intra-pair residual draw (the model’s chop_residual_v class) and √2-averaged noise.