Thanks very much for the clarification. I guess I got confused as I originally thought some folks were talking about fileing down the shorter stock CS bottom contact pin, so that after installed in the base, the base could then be screwed all the way to sit flush with the bottom of the device. But now that I actually have all the parts, I see that the Aspire coil already screws all the way down into the base, this of course after switching the shorter CS pin into the Aspire. I also used the CS white rubber insulator. So now I understand why you would say the top of the attie would have to be ground down for flush insertion. I won't be doing that as others mentioned, with the silicone wrap, you don't even know the base is not flush! So I simply went the simple route to start, swapping pin and insulator. Have not seen a leak yet, have had the bottom off a bunch of times so far.
GLAD you mention not going too tight when screwing the plug base back in, something I did not consider, will have to back off a bit, so many stories of leaks before I got mine, I did tighten it till it seemed to stop on its own, but that may be just a tad too tight and distort the internal chimney as you bring up, it never looked perfectly straight from my first look inside it before going to the Aspire switch, but it's been working fine so far.
BTW: As someone mentioned and was spot on ("throw out the first coil"), the CS pre-installed coil, started ok, then began flooding, I was sucking juice, and not having a good first experience, the 2nd included coil, which I properly prepped, tasted burnt from the first Vape, and I also start a new attie at the lowest wattage and slowly ramp up to break em in. Tossed that one quickly as it was not improving and taste awful. Also the Ohm's on the two included coils were HIGH at 1.8 and 1.7, grabbed one from the five pack and was 1.6, vaped ok. Then went to the Aspire BVC, all I have on hand right now are the now older NON-COTTON 1.6 ohm. As mentioned in this thread BETTER then the CS, and you save $$$. Going to order the newer Aspire BVC cotton wicked ones, also at 1.6. ohm. I do have them in the 1.8 ohm version but would like to stay closer to the devices 1.5 ohm specs for now. Hope the cotton ones Vape as well.
THANKS again!