I use fill holes on my tanks and it not only makes it easier to fill but it lets me vent when needed also. It seems that wicking can vary from carto to carto, some need no help, some need a little help, while others need lots of help. When I feel my carto going a bit dry, I can unscrew the screw in the fill hole for a couple seconds. I can see maybe 3 bubbles come out of the hole in the carto and then when a couple start coming out of the fill hole in the tank, I put the screw back in and the carto is wetter. Too many bubbles and the carto will flood. I drill my own fill holes and insert my own screws. Momandpopvaporshop sells the sub tanks with this setup.
And no, the top of the carto is not supposed to be wet. I do sytinge fill a new carto once I get it assembled in a tank and then fill the tank.
Dry pulls work too.