You know how when you installed FFXIV, you have allocated space on your storage drive space for FFXIV, for which the size of the main files generally stays the same unless updates happen? Glamour plates are, even when empty, allocated space in databases. Ignoring how to code the glamourplate-to-jobs logic in, this is something every single account ever created has allocated to them and must be ready at all times.

What you are suggesting is adding +660 glamour plates, by giving each job their own 20 glamour plates. This can't be made out of thin air, ya know. A lot of things would need to change on a system level to make sure this would go flawlessly, for every single character in their database.

Let's stay realistic for a moment and ask for "doubling" the glamour plates first, so we can actually have at least one plate per job and then some spares.

Also you posted in "Localization" which is just language/translation discussion.