Difficulty 29 and less: Snubs only
Difficulty 30 to 34: Snubs or Gunboats
Difficulty 35 to 39: Gunboats or Cruisers
Difficulty 40 and higher: Cruisers, Battlecruisers and Battleships
I actually find that this is a step in the wrong direction. People should farm remains in Omicron Psi, where there is actual danger, and not in front of their doorsteps where they are more than safe to just dock the ship that tractors the battleship remains. Make it actually necessary to visit Nomad space in order to experiment on Nomads, please.