OK lubed the hell out of everything. Gap is perfect now and mouthpiece turns easily

(although I believe Penelope's mouthpiece is smoother). Filled it with boba's with triple wick and it is
vaping perfectly mmmmm. Thanks a lot Imeo and fright.
Imeo one final question I noticed in zoranth's illustrations that when using ggts he is adding another 9x2 oring around the mouthpiece inside the refill big cap. Any reason for that? Maybe the rebuildable screws more inside the base and oring acts as early stopper?