Is elemental expression just bad?

So i decided to reskill my invoker from the cookie cutter stat stacking howa/potg lightning setup since I wanted to try something different rather than just follow other peoples builds. I decided to try a trigger build, got myself a choir and grabbed elemental expression coupled with CoC and CoS and got to work crafting a unique build. Let's just say my invoker is now a glorified paperweight, primarily due to my budget being all but non-existent at this point and I lack temporalis, but that's not the point. In this process i found a weird interaction, potentially bugged, where +to elemental skills gives 3x the value to elemental expression (the unique quarterstaff, specifically), probably due to it having all 3 elemental tags, which gave me high hopes for finally inventing my own gamebreaking build. But as you can probably guess I wouldn't be on reddit whining if I was crushing it in pinnacle. So, despite getting elemental expression to level 37 with an investment of 5 exalted orbs I found myself getting dicked down in tier 10 maps since, despite the impressive level, elemental expression does basically fuck all damage. Like, it doesn't even kill trash mobs properly in one trigger. Am i missing something here? One mediocre ring will add more damage to my flurry than elemental expression can shit out (not to mention dual heralds). Anyone know of a way/build to make this concept work?