Different Poisons - Questions and comorbidity

I'm playing ranger using Toxic Growth (TG) + Poisonburst Arrow (PB)
- PB have 3s Poison (so +50%), and I added Corrosion and Bursting Plague.
- So the poison that is better comes from PB.

What happens when for example, there is 1s left of Poisonbursts poison and Toxic Growth aplies poison? Is it 1s of PB poison then 1s of TG poison? Does it overwrite the better poison?

Then comes comorbidity. It would be easy to add it to the TG as it explodes few nodes at the same time. But would that change better poison from PB? Or maybe it should be changed and it could add a second poison. So PB aplies it's better poison and TG with comorbidity aplies a second weaker and 30% shorter second poison.

from my understanding the highest damage dot has priority then once that timer runs out the timer for the lesser takes over should work the same for ignite as well. not unless you have an item or node that allows more more stacks but still the highest damage dot should be the priority

Unless I'm clearly mistaken, the strongest poison in damage per seconds applies at a given time. The other stacks can still be kept in some sort of a queue (limited in time to your poison duration), but they won't do damage if you already hit you max stacks.

For example, if you have 6 max stacks of poison, and 6 come from your best attack and will last for the next 3 seconds, and then attack with a crappy attack that does trigger a poison somehow for 4 seconds, this crappy poison will stay in line to be triggered, but will not do any damage until 3 seconds elapsed (i.e. until your stronger poison have done all their dmg). Then, your weak poison will do 1 sec worth of damage before being removed. It wasted 3 seconds in queue.

In other words, no, I don't think you can overwrite a strong poison with a weaker one, but you want to keep yoir strong one active as often as you can, with as many stacks as you can.