So I got this Aeolus to sit perfectly flush on a mech mod. What I did was replace the bottom deck o-ring with one that's smaller/thinner than original. It still has some resistance while screwing the sleeve onto the deck, so hopefully it's enough to keep it from leaking out the base area. I'll drop some pictures bellow.
One thing about the atty is when it's sitting flush on a mod, you can no longer keep turning it clockwise to screw the sleeve off like it was designed too since the outer sleeve is touching the top of the mod and the deck is actually sitting above the sleeve. Screwing it clockwise while flush will force the outer sleeve tighter onto the top of the mod (I think, didn't wanna force it since I could just unscrew the atty from the mod like normal). I think that's why under normal conditions the sleeve is a little bit above the base of the atty... If it wasn't, the reverse threading wouldn't work correctly.
I always build on a ohm reader, and the one I have has a 510 popping out from the reader so when the atty is screwed on, the deck never touches the top of the ohm reader.
When I want to take the atty off the mod, I just take the top cap of the mech mod off, and unscrew the atty like all normal attys. this probably will not function the same way for box mods with stiff spring loaded 510's.
Atty sitting flush as can be.
O-ring comparison to the stock o-ring. I have a ton of o-rings laying around from past vape gear (I never throw an o-ring away), and I've been vaping for 3+ years so I got a lot. Not sure the exact size, but I believe this came from a AGT titanium genesis atomizer. It was a 18mm atty (or around that).
Picture of the new o-ring installed on the deck.
Picture of the ohm reader I use with the popped up 510 which allows me to screw the sleeve all the way down, which makes the sleeve sit a bit bellow the deck, assisting in making the atty sit flush on the top of the mech mod when screwed in.