Does anyone know how to change the armor visual spawns based on levels?

For example: By default, heavy armor changes at level 4 to be in the style of the "knight" class. At level 8, the heavy armor changes to be in the style of the "metamorph" class. At end game the armor will be in the style of the "fighter" class. This is all with the same treasure tables (I tested by adding a bunch of items to Magister Siwan in the tutorial and leveling myself up a bunch of times).

Would it be possible to instead have the "metamorph" style armor spawn at all levels (with stats being level appropriate)?