So basically make a glamour "materia" merged with the armor glamour plus the prisms that you can equip to a slot? (Was a little confused, but I know it's kind of hard to fit a detailed idea within 1000 characters..)
Anyways, if I'm understanding it right, the idea itself doesn't sound so bad; but, wouldn't it still pose a problem of carrying each said icosahedron/materia for each individual glamours you wish to save?