OK, I checked PoME. 84.125.23.220 is indeed right: it is the legend of the fate of Amrod (Telufinwë Umbarto/Ambarto), who was the one burned with the ships. Amras (Pityafinwë Ambarussa) survived and presumably still died in the Third Kinslaying. Now should we follow PoME strictly and have Curufin as Fëanor's fourth son and Caranthir as his fifth?