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OK, let's break this down step by step. Here's the good news, you pretty much understand it already.
Yes, the micro coils do allow more surface contact with the juice and therefore more juice to be vaporized at one time; however, it does not mean that you will have to go lower in ohms.
A good micro coil can perform similar to a "normal" coil (with spaced out wraps) that is nearly .5-1 ohm lower in resistance. That's not saying that your battery life will improve much since you will actually be heating up a larger mass of wire, but it shouldn't get much worse. As for the battery life, I would suggest trying a quality 18650 battery if your APV can use that size.
On that note though, I vape around 1.3 ohms with a dual nano coil dripper and my batteries last around 8-12 hrs before I start to notice a difference in performance, at which point they normally measure around 3.8 volts.
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Now using lower power on a lower resistance coil will be similar in performance to using a higher power setting with a higher resistance coil. I think the vv mods (from spinner styles to high end APV's) is something developed when people were using mainly stock coils from the factory, and still wanted to customize performance. Basically, if you wanted the same performance out of a 1.5 & a 2 ohm coil, all you had to do was adjust the power.
For the 2.3 ohms at 4.8 volts, that would be similar to around a 1.2 ohm coil at 3.8 volts. (Google "Sweet spot heat calculator")
As far as going to sub-ohm, the most of that is a cloud-chasing thing and I cannot advise that you even consider it with an 18350 battery as its pretty damn unsafe.
I guess the easiest thing would be to send you a coil or two and let you try them, nothing hard if you would like to give it a shot.
Hope that helps.