It would be nice to have threshold attributes for pi points. Then we could configure that values received from the source outside this limits would be ignored (not stored), substituted by the respective threshold value or even by an "Over\Under Range" state. This discussion is pretty old in the community, and I find it quite odd this configuration was never considered (of course there could be specific reasons I am not aware of).
The need for filtering negative values of a flow tag, for example, when summarizing data is very common.
See this discussion below for better understanding:
Users are led to believe that Zero and Span constitute these thresholds, but in fact they do not filter any value neither impact archiving.