Envision being stunned, brought near to death in the meantime. You have an armlet, and it is crucial for you to activate it. If you are a pro, you calmly wait to hit it right as you become unstunned. If you are a newbie, you might spam the armlet only to toggle it and immediately die.
The suggestion is simple. I would like to see a method for binding only activate or only deactivate to a key. So I could bind z to activate slot 1 and x to deactivate it. In that situation, now I could spam z as I am stunned, given my armlet is there, and not risk deactivating it. The way this will work is you can of course have an on bind, off bind, and toggle (i.e. regular as it is now) bind for each slot.