If you have filled a carto to capacity with the threaded end hole blocked, then cleaned it up, I would include blowing into the threaded end with the open end down then press a soft bunch of tissue against the top of the stuffing while the open end is still pointed down (or alternately if I think I have overfilled, I put the tissue in first then tilt the open end down and puff into the threaded end). Then I do the settle so every bit of the stuffing gets damp - I lay the carto on different sides, and set it on its threaded end over 15-20 minutes (and that is long enough with the thin juices I use). Then my cartos are unlikely to leak. However if you vape enough in a row to get the carto warm (which thins the
juice) and then stand the PV on end, it may leak. With a newly filled/settled or freshly topped off carto I may lay the PV on its side instead.
I can't help you specifically with the big cartos - no experience.
Meanwhile if you want to buy Boges, some of the places I buy them are
Liberty-Flights.com
LiteCigUSA.net
NiteLiteVapor.us
Crystal Clear
vaping