you are very very wrong about that !!! i have had this happen to me several times with my T3
the vacuum will suck the fluid into the coil chamber because there is a low pressure in that area also ,causing flooding !!
I can't argue with the fact that the adapter you are using might cause flooding, but what I do know is that it is not because of a "vacuum" created by tightening down the adapter. The coil area has the exact same air pressure as the surrounding air, unless you cover both the top hole in the mouthpiece, and the air holes in the bottom.
When you drag a vape, the pressure will ofcourse lower a bit, and that happens with everything you take a drag on.
It is possible that the adapter you are using doesn't let air through properly, which might end up sucking too much juice from the tank when you take a strong drag. But still, it's not tightening the adapter in place that creates the low pressure, it is the drag you take.
I would think that rebuilding a T3 head with 500 mesh would eliminate all wicking issues with high VG juices, but I haven't tried it yet with a T3. Everything I vape is 50/50.
Doing a SS wick on a bottom coil is difficult. A bottom coil is extremely sensitive to the replacement air resistance, so a hard material like SS will have to be made just exactly right not to flood. The top of the wick route is flat, so the wick can't be round or it will leak badly. Perhaps a SS wick with 1-2 silica flavor wicks could work well. I used a lot of time trying to get an SS wick work on a CE3, but it never lived up to my standards. The fact that SS mesh wicks so well might also cause flooding in time even if you get the fitting right.
My 510 to eGo adapters are not sealed, but I did seal the other one since the T3 can be a bit leaky at times. Easier to clean just the adapter instead of both the adapter and the battery connector. I used a metal rod that I pressed together to fit the inner part of the adapter.
Hm, just faced an odd problem with one of my T3's. I refilled it and vaped it for a while, then filled one of my other T3s. Then when I looked back at my first one, all of the juice was gone and I thought to myself "Didn't I just refill it?" Well, apparently it dumped out through the mouthpiece
I've also had bad leaks after refill. Seems that if I wipe the head dry, blow the remaining liquids through it, and then blow the insiders of the tank air tube to a tissue holding the tank upside down, I don't get leaks after filling. I guess there is just so much liquid all over after vaping a full tank. Coming to think of it, it does fit almost twice the liquid compared to my Vivi Nova Minis.