Keybindings Question and What's Allowed

I often find myself holding "Target Champions Only" and pressing "Player Attack Only Click" when there were many minions around and I didn't want to misclick or walk into the enemy team. It's inconvenient to hold these keys while casting spells and moving around. I have only so many fingers and it's disappointing that this key combination isn't offered in the client.

To reduce my finger strain and the awkwardness of it all, I've rebinded this key combination to one of my mouse side buttons. I've tried it in bot games and it's far more pleasant than holding both keys. My question is whether this is allowed in online ranked play and LCS etc.

Since it's just a simple control tweak with no combo executed, reading of game files, or fancy macro, I expect it's fine but I don't want to get in trouble or limit myself if I ever choose to play casual tournaments. This is why I'm asking for an official response and also suggesting it be offered as an option.

Thanks!