Pob fork: https://pastebin.com/9Um7n6kj
Disclaimer: I only play solo/with IRL friends, so this is technically SSF.

I don't give a fuck about meta, I play to have fun. I league started with this build in mind and created it as I went.

So, this is honestly my very first self-made build. So far so good, both the clear and single target feel good. I stumbled upon the combination of Sniper's Mark (spellslinger) + Pierce. You never have to think about what target is marked due to the fact that Marks are no longer a namelock skill. It also works beautifully because of how Subprojectiles work now: Split -> Pierce -> Fork -> Chain. The key part here actually comes from the previous league:

>For specific mechanics that had chances to occur or not occur, you'll now be able to fall back on another behavior the projectile has. Previously if a projectile had a chain remaining, the skill couldn't return until it had chained the last time even if there were no enemies in range to chain to. Now the projectile will return, and could still make use of the remaining chain if it hits an enemy during that return.

This means we can Pierce -> Split -> Pierce. Don't forget that Ele Hit has an AoE explosion too, which triggers every time the projectile hits.

So, despite not using any additional projectiles, our clear isn't affected at all, and in fact Pierce Support has a small more multiplier, so no gem swapping for bosses! I'm currently using an Immortal Flesh because I'm SSF and haven't found any rares that are better, and I have overcapped resists anyways. I also think that the mini-Glancing Blows boots (+5 block, take 20% of blocked damage) are good because I'm not block capped and I have ~15% Life Regen just chilling in my hideout. I also have a whopping 3300 Elemental Aegis. I'll admit that I've just barely touched red maps, but that's mainly because I haven't been playing much due to texture streaming issues.

Are there any glaring flaws I'm missing with this build?