Gas Arrow damage

Is Gas Arrow works the same as Caustic Arrow? In Caustic Arrow secondary damage is not dependent on weapon damage, but in Gas Arrow, the "cloud damage" it shows like its depends on weapon damage which is wierd because it looks like this isn't the case when i equip low dps bow, but with +3 projectile skills modifier it looks like cloud damage is higher, even when it shows on skill description that it should be lower.

Skill description is bugged or i just having placebo effect?

Hit damage does indeed cause larger Gas cloud damage. You want to focus on a lot of +poison magnitude and a high PDPS bow. Obviously the nodes that raise the number of poisons you can apply are huge, but magnitude and on hit are it's two main scaling factors.

As for having scatter shot increase the cloud damage, I think that's simply because it stacks the number of poisons faster. It's more a QoL thing. Ideally you'd want a high dmg Dualstring bow as it shoots multiple arrows allowng you to not have to use Scattershot, as you are lowering your hit dmg using it.