If you have assigned using a set at a master crafting table, you should only be able to craft that set until you change it, (Should not be the tabs for crafting without a set). That is done by not picking a set.
If you are doing a master crafting writ with the quest only check box checked it should automatically pick the set for that writ, without you having to set it.
There should also be another way to manually pick the set you want to craft in a alphabetical list rather than picking it by zone.
The way they are now I would rather not have the master crafting stations and just go back to the individual tables.