Question about damage conversion + ignite + resistance penetration mechanics.

I know that after damage conversion elemental penetration does not stack. For example, when you convert cold to fire, only fire penetration applies during damage calculation.

But what if I use a lightning skill with Stormfire ring, which allows lightning damage to ignite? While calculating ignite, lightning damage is secretly converted to fire damage, even if it's not an official conversion. Is it possible, in such case, to double dip elemental penetrations? Lightning penetration to make the initial hit bigger and then fire penetration to pump up the ignite dmg?

Thx for answers.

according to the wiki

https://pathofexile.gamepedia.com/Burning

"As a damage over time effect, burning damage itself is not a hit and cannot benefit from effects that require a hit, such as

Fire Penetration Support
"

I would think the lighting hit, applies the fire dot and would not work with fire pen.

It doesn't care about penetration at all.
It does care if you lower the targets resistance some other way though, like Elemental Equilibrium.
Also if you only use lightning damage + stormfire to ignite, you can just have EE and you'll benefit from it.
Also you can apply exposure to the target and this will give you more damage to the burning.