Personal anecdotes and mileage may vary:
I think if you can throw something on there that makes you look like a more well rounded candidate, go for it. I have a non aviation degree and that's some up and led to non aviation related conversations in interviews where I felt like they got to know me better, and I got to talk about something else I really liked instead of being an airplane operating robot. If you're going to volunteer though, make sure it's something you actually care about rather than checking the box
To tie into the other thread, work hard, but try not to stretch yourself too thin as well, especially if it's going to make your work suffer. There's a fine line between being ambitious and working your butt off and burning yourself out.