Properties of Page NS pages that can be accessed with the prp... prefix in mw.config are inconsistently available:
- prpPageQualityUser is only set in edit mode
- prpPageQuality and prpPageNumber are only set in "rendered" modes (i.e. view and submit)
This means that gadgets looking for this information will not work consistently during the edit flow. For example, a script that uses prpPageNumber will work in view, not in edit and will work again in submit.
I think all the properties should always be available, edit or not.