I'll see if I can be at all helpful
It's all about the resistance, and only the resistance. As temp goes up, resistance goes up. The mod does not measure temperature. The purpose of "setting a temp" or building those materials curves is simply to provide a way of translating a resistance number into something familiar, temperature. If your connection is bad, the mod may read that incorrect resistance and assume it's "at the right temp". The truth is, the actual temperature of the coil doesn't matter, only the set point you've chosen such that the wire is 'hot enough" to vaporize your juice the way you like it. Comparing temps between say different tanks, even on the same mod, is meaningless as 450F on tank A will not necessarily perform the same way as 450F on tank B. Each tank, each coil build, will have it's own sweet spot.
The advantage to TC isn't so much achieving a given temperature, but maintaining that temperature throughout the vape. In power mode, the longer you hold the fire button, the hotter the vape will get. Eventually getting too hot to vape, or even begin to 'burn" the juice. With TC, once at temp, for as long as you hold the fire button, the temp should remain the same, giving you a smoother vape.
The higher the TCR, the greater the change in resistance to temperature. So it's theoretically easier to tell the difference between two points with a wire of higher TCR. SS430 has a higher TCR than 316L, however, a DNA board is capable of handling 316L well, assuming the resting, cold resistance is stable (see connections). In addition, the small changes in resistance are easier to "read" the higher your cold resistance starts at(within limits, most mods won't do TC on a high ohm coil). Low resistance builds, like the 0.25 ohm dual coil cross stapled traintrack Clapton coils will be tougher than a 0.5 ohm build. In truth, when using TC, the resistance is immaterial to performance assuming you've built within the range TC works at.
My typical build would be 0.5-0.7 ohm on 316L. Reads well, performs well, for me. Going back to your situation, you went from a 3 wrap 28G coil, to a 6 wrap 28G twisted coil. Essentially, 4 times the mass that needs to be heated to your preference over your first build. Comparing their performance under TC is difficult because they're going to need significantly different amounts of current to achieve the same "temperature". And you changed materials from 430 to 316L.
So you've played with multiple variables through this and found inconsistencies, which I'd be amazed if you didn't. Best way to try and get some consistency is settle on one wire type and build. Be sure your connections are solid. Vape a juice you know well. Then start changing your settings and see where you get a solid vape. When you have that, you have a basis to make a single change, and draw an accurate conclusion about what's working, and what's not, to suit your particular preference in a vape.
That is exactly what I think of how your explaining it.
