Recently, ever since I tried out spaced coils, I have stopped using micro coils. I now spaced my single 24-26 gauge coils, usually from 0.4 to .7 ohms (depending on RDA) about same diameter as the coil gauge, vaping from 20W onwards .
You can spaced them more to 2 or more times your coil diameter as long as you don't get hot spots, especially towards your terminal posts.
It really does not have to be evenly spaced, as long as there are enough gaps for the vapour to escape.
The vapour production are not necessarily more, but you'll definitely get much denser clouds.
Interestingly though, its not what which is apparent to the eye.
My observations are that Micro or tight coils appears 'Impressive' when you fire, shooting fast, massive clouds in more narrowly-focused direction which appear thick, whereas spaced coils appears less and tends to emits in all directions and evens makes slowly 'pops'.
However, vaping it is another another experience altogether. Bearing in mind that all these 'fireworks' are before you put the top cap on and goiing through the amount of airflow through inhalation.
One probable explanation I can think of is, that vapour from the tight micro coils is losing some steam and flavour as it has already being burnt into finer mist and higher temperature, before being accelerated further while you inhale.
Whereas the more sparsely emitted vapour from spaced coils ended up producing thicker clouds, when it passes through a narrower channel to the drip tip (relative to the same setup), while retaining more flavour at a cooler temperature, which I prefer.
That is the reason why stock sub-ohm RTA coils and RDA deck coils (that come stock with subtanks etc.) are spaced, I realized it offers many advantages such as thicker clouds, deeper flavour and able squeeze in more cotton while going to higher wattage without getting burnt taste. You get the best of both worlds.
Didn't realize what I've been losing after being a hardcore advocate of tight, 'tensioned' micro coils for so long, LOL.
Have fun and be amazed, just keep experimenting.