What about Nerfing the time from 7seconds to 4 seconds.
Change it so its 2/4
2: Single target Champion with the Highest amount of items.
Selects a random hecttech, if they die, they'll send the aoe around the area disabling the items for another 4 seconds.
4: Single target Champion with the Highest amount of items.
All Hect techs will get the bonus effect: IF a Hextech Dies, they will send a small AOE Effect that will disable the items for another 4 seconds)
So its just to make it more consistent, but not disable the entire parties items if they pick the champion thats near the center.
Make it so it does't last as long, but its more deadly in the mid and later in the fight.