A lot of articles about this topic are too wordy, technical, and generally confusing so we will keep it short and understandable.
Let us dispel a common misconception: you can vape nicotine salt liquid in a sub-ohm tank. In other words, nicotine salt e liquid is not purely for pod vape kits. The only thing you need to do is make sure to vape a low nicotine liquid. Say a 6mg/ml nicotine salt eliquid. This will vape quite nicely in your sub-ohm tank. You’ll need to play around with the wattage to find your sweet spot, but that’s it.
The opposite is also true. You can vape e-liquid made with normal (freebase) nicotine in pod vape systems. You could, as many people do, vape, say, a 3mg/ml freebase eliquid in your pod kit. Or a 6mg/ml liquid, if you wanted a harder throat hit.
Since the late 2010s, eliquid made with nicotine salts has been mostly used in pod kits, but there has always been a considerable amount of vapers using nicotine salt e-liquid in sub-ohm tanks.
So what it comes down to is, you can vape either kind of juice in either kind of vaping system. You just need to keep in mind the different vaping systems and nicotine levels.
Hope that helps!