Controller keybinds

Greeting, I tried to connect a 'ShanWan Double-USB' controller, Minecraft PE recognises the keys as those purple-black blocks. I binded it and worked fine, until I tried to manipulate inventory. The inventory keybinds were normal, and I couldn't change it. It's pretty a hefty problem for me. Can y'all add ALL keys bind system? Like, add a legendary 'Advanced' button on keybinds for inventory, emotes, and menu, it would be amazing!