Seriously.
I've seen just one too many Goldaruma spawn outside walls, inside walls, up on cliffs in cave dungeons, and on the other side of barriers. It's irritating. It gets worse when they run PAST the portal to the next room, and you can't do anything but shoot them, something that isn't enough to kill them on their own.
Yes, they're meant to be difficult to kill. I know this, I wrote an entire guide out about them when they were first introduced. But that difficulty should come from them alone, and not how far they spawn, and where they spawn. There should also be a visible timer for how long they stay until they despawn, not randomly, because everyone here can attest on how irritating it is to see them spawn, only to immediately despawn without you doing anything to them.