What I'm asking is, what are the benefits of sub-ohming on a DNA device? You say "You need to sub-ohm to take advantage of the 30 watts". How so? 30 watts on a 1.5ohm build is 30 watts on a .5ohm build. What's the difference?
A specific example; I build my dripper with dual coils that come out to .5ohms. Then I build another dripper at 1.5ohms. I fire both at 30 watts. What difference am I going to see? They're both giving me 30 watts.
The difference is the battery is outputting vastly different voltages with those two atomizers.
In your examples:
If you set your DNA (or whatever regulated MOD you have) to 30W with a 1.5Ω build, the battery will be discharging 6.71v to the atomizer, which will likely be way too hot a vape for the vast majority of people. With a .5Ω atomizer set at 30W, the MOD will discharge just 3.87v to the atomizer, which is likely too cool a vape for many (if not most) people.
When sub-Ωing you need to have higher wattages so that you can have adequate voltages in order to fire the coil at a good temperature for vaping.
Were you to lower the resistance of that atomizer even more to .3Ω, it's unlikely that the coil will even fire because the MOD would be discharging just 3v from the battery if it's set at 30W. A DNA device (or any other without step-down circuitry) won't fire it at all.
But perhaps even more importantly, sub-Ωers (and those who don't sub-Ω) like regulated devices because they provide a smooth, robust, consistent vape throughout the entire charge of the battery from the time you pop it in until it gets cut off at 3.2v.