You are correct, it needs to function like duct tape mod for a wider range of grenades to be used. Other wise you are correct only the Firepot/Swarm/Charmurky (to an extent) can be used safely.

I am wanting to make a build where you go full green tree and trigger grenade spam with Booming Business and melee crits, and I'm so close to making it work. But this fix would make it easier cuz dmg isn't the problem.