Usually in selfmate problems white has material advantage to be able to force black to checkmate white, so white likely has a conventionally better position or has a forced checkmate. But not always, as this example shows: Position where neither player can force a win and neither player can force a draw .
But in general, does having a checkmate imply having a selfmate or vice versa in most cases, and in what conditions is it not the case? If both sides play with selfmate as the goal, then either one side can force a selfmate or both sides can force at least a draw/not lose(here "loss" means checkmating the opponent), analogously to normal chess. So any position is potentially a selfmate for one side or "drawn". How are the set of positions that have selfmates and the set of positions that have checkmates related?