Yoshida recently responded to this same question during the "Hear me out Yoshi-P" event at Niconico Chokaigi 2015. Here is the response that he provided during the event:

This isn't impossible; however, in order to make this happen it will require additional space for saving character data. So instead of creating additional space specifically to be used for glamours, we would like to prioritize increasing the size of the Armoury Chest which uses the same space for saving character data. Equipment data is checked on the server side, and as such we can't simply store the information on the client side. This request will require more data to be transferred back and forth, so if we're going to increase the amount of data stored on the server, I believe the better option is to increase the size of the Armoury Chest first.