By "not applied" do you mean you suspect the directive is being silently disregarded by the placer? Or the placer isn't honoring your request as judged by visual inspection?
If you suspect it's being silently disregarded check the value with "reportInstPad" to make sure the padding you requested is still there.
If you suspect the placer isn't honoring your constraints, consider a few things:
- The value is specified in placement site units
- The padding isn't guaranteed to occur on a specific side of a given instance
- You can see what the unit size looks like visually compared to the cells by turning on placemen site visibility: All Colors->View Only->Row Site Pattern
I suspect that the value of "2" is just really small. Try a larger value, like one which equates to 50-100% the size of the instance you want padded.
Hope this helps,