What is it with players who disconnect in losing or lost positions? Is there some advantage to this? Why not just resign. We all lose games. This seems unsportsmanlike and a waste of time.
I think it isnt wasting of time, because this tactic can save many rating points.
For example:
ru.lichess.org/forum/general-chess-discussion/my-opponent-cheated?page=1I always block such players, even in blitz, wasting the opponents time as a revenge is a sign of a dishonorable person, I don't play with dishonorable people if I can avoid it. I block trash talkers also.
So just block them is my opinion on the subject.