Do you need to be a real social butterfly to convert a VS? I'm on my second vac scheme in a row and already exhausted and I can feel myself not putting myself out there as much as I did on the previous one. I'm starting to worry that my relative lack of networking is going to be a deakbreaker especially compared to what I'm seeing from my fellow vac schemers, who seem to be closer with their supervisors and others in the department.
I would say you should put yourself out there - the scheme isn't only for you to do tasks for 2 weeks. That being said you shouldn't network simply for networking's sake i.e. you should have [good] questions to ask and be interested in people, also bring a notebook everywhere unless it's not appropriate. I have heard of candidates who spent their whole scheme having coffee chats and didn't convert their VS, and those who had them sparingly and did convert. There isn't really a one-size-fits-all method—just avoid pointless conversations (if you're scheduling time for a chat specifically) as lawyers' time is valuable. Obviously this also depends on the firm as they may have different assessment components they're looking for - but generally as long as people have a positive impression of you you should be fine in that regard.
Good luck with the VS and good luck with the results from the previous one as well!