Combining banners with chestplates for more personalisation

Since the new update adds armour trims for more personalised armour, I think it would be perfect to be able to combine banners with chestplates to create unique capes. It fits in with the theme of the update and would give banners another use while also expanding the personalisation possibilities beyond the world's build limit. It would also be pretty neat if trims could be applied to the banner itself. So you could have some crazy design with a shiny border highlighting it.

Also, trims on shields. Maybe.