I actually understand that fairly well and if I’m correct in what you’re saying, it would have been almost easier to go with regulated despite being completely overwhelmed by everything.
You have a regulated device. Let me go all the way back to the basics to help you understand a bit as to what's going on. Maybe it'll help you understand what is happening. Things will be over simplified, so to all the experts, I know there are many but's to it.
Ecigs work by creating heat through a wire that "boils" juice. When people want more vapor, they have two choices. One, is to simply put a second (or more) wire in, effectively doubling the vapor output.. but it also doubles the power requirement. If you have a .6 ohm dual coil setup, you essentially have two 1.2 ohm coils in it. The battery doesn't care what setup you have, it just works with the final result.
Another way to get more vapor, is to use a thicker wire. This, however, lets the electricity flow more, as well as have more surface area to heat up. There are plenty of other ways to increase surface area (ribbon wire, claptons, etc), but in the end, it's what the user likes that is more important.
Think of power as a water pipe. The voltage is the speed of the water... say 5 miles per hour. Think of amps as the size of the pipe. if you had a large pipe filled with water going 5mph, you're pumping a lot of water. but if you had a tiny pipe with water going 5mph, you will be pumping little water. Ohms would be resistance.. Think of it as the faucet. if you open your faucet all the way, the faucet isn't restricting the water as much, so it would allow for a lot of water to go through. AKA, you would be using a lot of power. If you opened the faucet a little, you would be restricting the flow more and less water comes out. AKA, less power. Now, think of wattage as gallons per minute. So, if you wanted 5 gallons per minute through a small pipe, a regulated device would automatically determine how fast the water should go to get that 5 gallons per minute. if you switched to a larger pipe, it would change the speed again... but the output would always be five gallons per minute.
Now, with batteries, they provide 4.2 volts fully charged. As they drain, they provide less power. With the low point being around 3.4 volts. at 3.4 volts, the battery is considered drained. Any lower and it can permanently damage the battery. most devices have a cutoff at that level. Your mod changes the wattage/amperage to try and get a constant 4.2 volts
Now your device does not have any control over regulating the wattage. I cannot determine what factors it decides on what wattage it uses. If I had to take an educated guess, I believe it will try to output 4.2 volts no matter what the battery charge is at and no matter what the ohms are. As long as the specs are within it's limits, it will change the wattage to get the 4.2 volts. If your ohms are high, like .6, it will lower the wattage to give you the 4.2 volts. However, if your ohms are low, it will raise the wattage to get the 4.2 volts. If you decide to get wild and put a real low ohm coil in there, you'll run into other limits. Again, I am totally guessing at this, but I would guess it has a 15 amp limit. So even if you put.. say a .1 ohm coil in it... it would run into an amp limit, and be forced to run at a lower voltage resulting in quite a lackluster vape.
In the end, I think it is very much like the Smok AIO, but with a replaceable battery and atomizer. if I had to recommend a battery for it, the LG HG2 is a 3000MaH battery that has a 20a rating instead of the samsung 30Q's 15a rating... so, it should be a bit safer. Of course, if you run the .6 ohm coil, you won't be getting anywhere near the ratings of either battery, so you probably couldn't tell the difference between one or the other. If you wish to actually control how much power you use, there are a slew of single battery 80w mods out there. one of my favorite and go to mods for single battery is the
Eleaf Aster 75W TC. It's been out for a while, and there are still plenty of others out there like this.