Unrest threshold values/feature are broken?

[EnPhreg]

hi guys,
i've played around a little bit with the unrest threshold values (building outputs and race specific values).
and it seems that this values have absolutly no effect.
if i understand this feature correct, than the values should lower or increase the threshold for a possible rebellion in a system.
but this don't works.
for example: the mizerians have a unrest threshold 0, but they also getting randomly rebellions once their moral level is at rebellious. like all the other minors or colonies. also giving buildings a high bonus for postive or negative unrest threshold won't channging this behavior.

maybe this feature is unfinished or just another broken feature? maybe it could be simply activated with some small code changes?
maybe it's worth a brief look?

EDIT: maybe the feature was also only intended to lower or increase the effectiveness of the unrest order "buildings" (inquisition, tribunal...).