flow sensor sync with gyro

[omri0912]

i understand that optical flow sensor calibration calculates the ratio between the optical flow pixels/sec and the gyro degrees/sec at AGL of 0.5m (altitude above ground).
once this is done, the optical flow pixels can be converted to degrees using this ratio (function opflowUpdate).
my first question is - is it true that the ratio would work only at 0.5m altitude?
i also see this code in function estimationCalculateCorrection_XY_FLOW():
fpVector3_t flowVel = {
.x = - (posEstimator.flow.flowRate[Y] - posEstimator.flow.bodyRate[Y]) * posEstimator.surface.alt,
.y = (posEstimator.flow.flowRate[X] - posEstimator.flow.bodyRate[X]) * posEstimator.surface.alt,
.z = posEstimator.est.vel.z
};
here the gyro body rate is subtracted from the flow rate.
my problem is that this is done before adjusting the flow rate for height. i expected to see this code instead:
fpVector3_t flowVel = {
.x = - (posEstimator.flow.flowRate[Y] * posEstimator.surface.alt / 0.5) - posEstimator.flow.bodyRate[Y],
.y = (posEstimator.flow.flowRate[X] * posEstimator.surface.alt / 0.5) - posEstimator.flow.bodyRate[X] ,
.z = posEstimator.est.vel.z
};
am i wrong?
my code adjusts only the flow rate for altitude assuming flow rate is pre-calibrated for 0.5m height.