Braiding longer wigs is a little bit like braiding normal hair: it's a pain in the bupkis to keep it nice and neat if your hair isn't nice and neat to begin with. Wig braids will can get flyaways, particularly with snags and static. I've heard storing wigs with dryer sheets can actually cut down on the static significantly, but haven't tried that yet.
That said, I've always put hairspray on my braids once I have them done to set the style a little bit, and even painted in some dilute hair glue at times. OTOH, I've been dealing with the massively ridiculous monstrosity that is Unohana's braid, so yours may be more cooperative.
And here's what I spent the last few weeks going bonkers over trying to get wearable. I got it done for ALA, though I have a crapton of things to work out and fine-tune now. The intent was to wear it and work out the kinks, though, and that did happen!