I think it would greatly increase the usability of the Clear IPTC Stationery Pad Fields dialog to have the top row (Clear field and Clear apply) tabs to check all items in the respective column.
While All and None does check/uncheck all checkboxes the two top row tabs could toggle the Clear field and Clear apply checkboxes separately not to need clicking all the individual checkboxes in a row.
It would also greatly increase usability to have the ability to save snapshots in the Clear field and Clear apply dialog.