I notice that plasma is largely ignored in PVP because
1) Omega anti-borg shields all carry 15%-20% plasma resists
2) Plasma fires are instantly removed by any Hazard Emitters
I find #2 above quite strange since it is 100% effective regardless of how many plasma fire stacks are present or the hazard emitter level being used. Here is a proposal: How about making plasma fires more persistent by allowing only 1 plasma fire stack to be cleared per level of Hazard Emitter being used per second? For example, Hazard Emitters 1 can clear a tripple plasma stack in 3 seconds, while Hazard Emitters 3 can clear it in just 1 second?
The above change still won't put plasma weapons on par with phasers, disruptors, or any other energy type, but it will make plasma fires just a little more effective without being game-breaking.