Quote Originally Posted by Nektulos-Tuor View Post
They would only be horizontal if said boss took the same amount of damage regardless of type. So a well-balanced proc would be instead of a fireball, it would be a boulder that did physical damage.

Gear A: Adds an extra attack that deals X damage.
Gear B: Sometimes attacks three times dealing damage.
Gear C: Occasionally launches a saw that deals damage.

It shouldn't matter what type, unless all the types are the same. If they are different then its unbalanced procs.
You basically just described the purpose of crit, det and skill/spell speed. Different ways to deal damage and heal but all are viable if the stat budget is the same. That means the game already has horizontal progression in cases where an item has random secondary stats (like leveling accessories) or sidegrades of the same item level. Are you asking for more sidegrades? Or do you want to be able to meld all gear to have a choice between stats?