That's about 30,000 light years ago... resurrected Ballard caught up with Voyager pretty easily, eh? And with not knowing where exactly to find them. And her new father was right behind her. Yet no one asks about the method of travel, or examines her shuttle? Could have easily shaved the last 20,000 light years off the rest of the trip.
Yeah, really. If we take STO as canon, they were able to dig up dead Harry from Deadlock and reanimate him as well. And who knows, maybe Seska, Suder, and the dozen Kazon he killed have become members of their society as well. Not to mention any other crewman who died with a relatively intact corpse. One wonders if any species actually turns their dead over to the Kobali, to give them a second chance.
Speaking of fast travel, something else I thought... Species 8472 had to be able to emerge from fluidic space pretty close to the Federation to be able to replicate Starfleet Academy so perfectly. Maybe the laws of distance were different there... maybe they could have taken a detour through fluidic space and gotten home that way.