Volkuurs guidance + cospris will = 80% chance for lightning spell hits to poison?

Volkuurs gives "Lightning damage can poison" and "lightning damage has 20% chance to poison on hit"
Cospris will gives "60% chance to poison on hit".

So combining those two items does it mean that my lightning spell hits have 80% chance to poison?

This is how i see it but im not sure. Its kinda important for my new awesome build to get an definitive answer to this.

I am almost certain that your lightning spells will only have 20% chance to poison.

https://pathofexile.gamepedia.com/Poison

Only physical and chaos damage can poison. So all normal poison on hit modifiers will only apply to physical or chaos damage.

Just like Starforge would allow your physical damage to shock with shock chance, will Volkuur's Guidance allow your elemental damage to poison with poison chance. So yes, generic poison chance will increase your chance to poison in this case.

Since you get a "lightning damage can poison" mod, every generic chance to poison should apply to lightning damage as well. If that is not the case, the wording is very misleading.

Thanks for the answers.