I have had to learn about Multi-crew and the quirks or some of the bugs that come along with it by trial and error. I have two accounts, the 2nd of which was brought on-line when they first updated with the Multi-crew, solely for the purpose of linking both my accounts together and whatnot. Well, in the beginning, didn't work out so well with all the dropped connections and it was just a pain to deal with. So I just turned the 2nd account into the exploration arm of the Main account.
Well, we are now present day, and its been a few years and decided to try to merged the accounts again, but my old laptop was just not up to the task of running Elite anymore. Would take upwards of 30 minutes just to load the game, and if it did load up, was choppy as hell, forget about trying to multi-crew with it. So I bought a new heavy duty laptop and surprise, the game loads spectacularly on it. Now I link them both all the time, to multi-crew or wing missions such as go fetch or cargo delivery missions, or mostly just wing mining LTDs. Great fun.
Which brings me to the Quirks. I have found, and maybe everybody already knows this, but you can share wing missions with your multi-crew, and they can accept, and after completion, can travel to that base and get the rewards. But, since they can't access the station screen while in multi-crew, they cannot get their own wing missions to share with you. And you can't take a mission before multi-crew, then try to share it after multi-crew since any missions you may have in your transactions won't show up.
Another quirk is the amount of chairs available in the ship you are flying, most have just room for 1 or 2. But if I have my alt account multi-crew, and my crew takes up the 2nd seat. If I try to add another player into that 2nd position that my crew occupies, he will be able to load in, but will be unable to really do anything because the crew is mucking up the code. So if you're gonna have live people multi-crewing with you, then make sure you leave your crew at the station.