I agree with you. Spaced or not spaced they heat from the middle out. The greatest resistance in a resistor which is what were dealing with is in the middle. Thus the most heat generated will be in the middle wraps. A simple dry burn on any coil will confirm this.
That's absolutely true on an absolutely dried coil and with their wraps near enough. But once you space them enough, or if the wick is wet enough (and I should remember you that you vape with enough wetted wicks...), you'll get an evenly distributed heat dissipation.
That's why, at least with nickel, with the highest TCR in play, it is preferable to wrap spaced coils instead microcoils. Even wet and properly fed with not so much current, they are prone to overheat a bit in the middle, because there is less heat dissipation and more heat density if the wraps are not enough spaced, and with Ni-200 any temperature raising automatically adds noticeable resistance and aggravates the issue, and that ruins any consistent and precise temperature estimation based on resistances. Which, if you are sure that the maximum temperature is somewhat related to the mean temperature as it is seen by the mod, and it is not a dangerous one, is not so big problem.
That is how we've been vaping for some time, adjusting wattage (on mechanicals with resistance, on VW keying the proper wattage after some trial and error), and TC just adds the 'I'm detecting a somewhat dried coil, Sir!' warning.....
...not less, not more....
Well, I like it, as it smooths the vape in any atomizer, rendering the same exact vapour stream with the same flavour and throat-hit along almost all the atomizer moisture states, and it warns in the end, just with less vapour. It's a pity that some folks find it damn difficult to adjust and to get proper results, and it appears to be a bit too-technical to get it, because if it were plain-adjustable with some basic rules and just one button it would be the ideal noob-proof vaping technique...
...but it is not, not yet. Maybe some day.
Last night I ventured to resuscitate my Fogger (v2!) and I put a Ni-200 AWG 32 twisted (three wires strongly tightened with a power drill) and wrapped over a 2.5 mm core on it, which barely fits the housing, but at 0,082 ohms if works like a charm at 15W/230ºC -200 ºC on the IPV D2, more on that later-
It is not a sub-ohm RBA, it is from one or two generations before all this craziness about vaping RBA at more than 30W, but it works, once you accept it cannot provide more than 20W, in any circumstances.....