Better offhand slot in Minecraft Bedrock (now a good solution for mobile)

Ok, i already posted a comment about this but i didn't count the touch to interact mobile people, but i have an idea: what if, when you put a block or useable item in the offhand, there would be a main hand preference. What i mean is that, if you have a block on the off hand and a sword on the main hand, for example, you would be able to place blocks with the off hand just by touching the screen normally, but if you had a useable item or another block on the main hand, you would place/use the thing in your main hand with preference over the off hand just by normally touching on the screen. or maybe, another solution would be to add a toggle, that when pressed while touching the screen, would put a 100% preference on the off hand while pressed, so even if you had another block or a useable item on the main hand, you would use/place the thing on your off hand while pressing the toggle. and of course, on keyboard and mouse or controller, just add a toggle for it