Vine Arrow Combo

I'm having a tough time testing things with vine arrow. It seems like multiple plants don't stack their damage, nor does poisoning multiple plants cause them to channel additional damage onto the enemies.

I'm also unable to get Corrosion to work with the vines, it seems that poisoning the vines causes them to channel additional damage into the enemy, that damage isn't considered poison, so the armor break doesn't stack.

I understand corrosion not working with the ability as the enemies are technically not poisoned by the vines, but it seems like an oversight that multiple instances of the vines don't deal additional damage, and multiple instances of poisoned vines not dealing turbo damage.  

Does anyone have any good combos with Vine Arrow to help me get past a plateau?