Have any of the alternate proton torpedo or concussion missiles made it into the game?

Ion Missiles, Advanced Torps, etc.

I don't think so, but I figured the right combination of mods could easily describe a different weapon. Add Accurate to a missile launcher? Call that Cluster Missiles, as it's more likely to hit, and also more likely to trigger Blast or Guided.

Dangerous Covenants (an Edge sourcebook) has alternate missiles.

I've introduced a kind of specialized missile that explodes in a cloud of tracking beacons linked to a specialized sensor that detects power systems at close range with the whole thing encased in a hardened penetrating case. So they do half damage of a standard concussion missile but the tracking beacons can detect if they are lodged in a vessel or floating in space. Only those that hit send a signal making it possible to track down a vessel that thinks it has escaped by the skin of their teeth. I introduced it for the Polis Massan adventure in the Strongholds of Resistance book so they would have a way of tracking the TIE Phantoms back to their base and take it out. They loaded them in the aft facing missile pods and fired them in salvos of five at a time at the attacking Phantoms.

BTW, those missile pods introduced in Dangerous Covenants are wicked powerful. I highly recommend them.

BTW, those missile pods introduced in Dangerous Covenants are wicked powerful. I highly recommend them.

Depending on how tight your game is on credits, blowing 2,500 per shot might seem like an excessive cost. I think it's well worth it, but some games will vary.