How do you feel about the following:
If guns are holstered, Stim gives +40% speed.
If guns or ordinance is in hand, Stim gives only the current +30% speed.
This way Octane as an opponent would remain the same as he is now, he couldn't attack or even reload if he wants to keep his higher speed, if he wants to fight he has to come back down to the speed we're used to. Speedy strafing while unarmed isn't that bad for the opponent as the tradeoff is Octane's offense. This might not even boost Octane's efficiency rating but speed is life amigo.
I understand if you can't give an opinion on it but maybe you could just say you've read it?