PoE Caustic Arrow, Physical builds

I have been playing a Pathfinder, Caustic Arrow Ballista poison build for a bit now and I am liking it a lot. It was not my league starter, but I am thinking of starting it next league as my only character. ( i normally roll a bunch and get bored of it in T16s.) All the gear is super cheap and available. My question is around elevating it more than it is. I think that it is pretty much at a plateau as the upgrades are super expensive, but I was hoping there was some weird interaction that I was missing that would up the DPS. Survivability is great, so no problems there. I imported my ch

==================================================================================================================== GENERAL TIPS ==================================================================================================================== Bandits: Kill All You can mule (make a level 1 character/kill Hillock) a Ranger on league start for a G-G Bow + Pierce gem to help you level with Caustic Arrow You get FREE respec points as you progress through the campaign. Use these to respec your starting nodes (see 94 point tree) The items in this guide are are a GUIDELINE, listed with the ma