I've read that gamma ray bursts from black hole formation are emitted in a narrow beam, and thus can be detected from very far away. What happens in the case of neutron star collisions? Is the gamma ray burst emitted in a narrow beam or spherically in all directions?
I went and re-watched the PBS Spacetime episode on neutron star collisions, and while he didn't address this specifically (at least in that episode,) there was an animation that seemed to show beams emitting from the poles. I think it's the case that the gamma ray emissions follow that pattern. IIRC, it has something to do with the magnetic field orientation. (I'm just a lay person entertained by cosmology, so not very confident.) Above a certain combined mass, neutron star collisions are one way that black holes form, so that would line up with what you said you read.
Same deal, two beams shooting out the top and bottom of their orbit.