  In a recent paper in this journal, Lingam and Loeb (2018) develop an
excellent heuristic for searches for biosignatures vs. technosignatures. We
consider two ways in which their approach could be extended and sharpened, with
focus on durability of technosignatures. We also note an important consequence
of the adopted heuristic which offers strong support to the ideas of the
Dysonian SETI.
