dubious daily tournament tactic: throwing game to weaker opponents

Suppose I'm in the semi-final round of a tournament:  2 advance to the final round.  Suppose I've locked up a position in the top 2.  Two other players are contesting the other spot to advance, and I'm still playing the weaker of the two, having finished very tough games against the other.   What do I do?

If my goal is to win the tournament, then the answer is obvious: throw a game.  This would help the weaker of the two players advance to the finals, eliminating the stronger player.  Then I'll improve my chances in the final where I'll need to play the other advancing player again.

But I feel as if this sort of game theory optimization is wrong, on a variety of levels.  One is it's unfair to the stronger, faster player, who deserves to get into the finals.   The other is it "rewards" slow play by my present opponent, since had that player played quicker, I'd not have had the luxury at that time of being able to throw a game against them.

So obviously I should play my best game, against all opponents.

This hypothetical shows one of the many problems with the present daily game time controls.  It's too easy for players to drag the game out for tactical reasons.  We don't want games to drag out.  This is why I've proposed a system where players need to average a certain movement rate during games, in addition to providing a maximum time per move.