Perhaps, if they were to make a passive ability stronger it would need to be Simmering Flames. Cauterize works fine the way it is. If Simmering Flames greatly decreased grenade and melee cooldown (similar to how the Catapult modifier works) it would allow Sunbreakers to be very strong in both PvE and PvP without ever needing to use their super, a double edged sword in a sense. This way it would feel like using the Tlaloc, the weapon is very very effective when you hold onto your super.