I had/have a bug in my code. Not 100% sure what it is yet, but my guess is that through a bit sloppy coding, I ended up with players that are linked but not inuse, directly when a fresh player connects. Naturally that's on me, however this cascaded into a more serious error which it probably shouldn't.
torsoAnim ended up being sent to the clients unconverted and as a result clients crashed.
g_multiversion.c converts whenever ent->inuse is true. however probably more logically the check should be for ent->r.linked, because that's what the engine uses to determine whether to send entities to clients.
So in no way am I blaming my bug on mvsdk per se, but am I wrong in assuming that checking for r.linked would be more appropriate?