You only lose your cargo if you are within range of another player. So unless you somehow disconnect in Manhattan orbit or similar places, you won't lose your cargo or anything. Even if you disconnect in front of players, the cargo will either be there where you were, or someone takes it (you can just ask for it back).
Edit: I have a 500ms <10% loss/lag connection to the server, and this plugin doesn't worry me. I hardly encounter players anyway while trading so I won't stress if I disconnect.