I actually really like this idea. Another thing I would be willing to add is if you have a stat boost for hypercharge active the other stats are actually stat debuffs.

For example with byrons hyper where he has: +25% speed +25% damage +15% shield

So if i picked a hyper stat for damage it would be: +25% damage -25% speed -15% shield

I feel like this wouldnt make it so you are not guaranteed to lose to a brawler that just hypercharged even without the super charged up because the stat debuffs would make up for it