The lefthand of the minecraft bedrock edition

I've been playing the minecraft bedrock for a long time and have an idea how to improve the left hand of the bedrock edition so that you can use objects in the left hand just like in the java. you could add an extra slot to the mobile phone edition (the left hand) which you could then use by pressing it. For example, you place a rocket or a torch by pressing it, or you use it to hit  with your sword. On the console edition, you would have to press the shoulder buttons (e.g. L and R on the swich edition ) at the same time. so you don't have to add an extra button on the Handy Edition (except  the left hand)