As someone who has been on both sides of the types of scores listed above I want to add my 2 cents. Being on the short end of score, most of the time it was our team that caused the other team to continue to score, meaning that we kept throwing them the ball even when they had backed off to half court then inside the arc and at times we'd have kids not get back and/or allow the other team to score lay-ups. I don't want any coach to tell his kids not to play hard as his/her subs deserve the opportunity to practice how they will play, to a degree. As someone who has been on the larger end of the stick, when we back off to half, then inside the arc and the other team continues to throw the ball directly to our players, or doesn't go after rebounds or loose balls, doesn't even stand in the key to stop dribble penetration or cutters then it's not our fault for the score.
I do the like the idea of a mercy rule running clock in the second half where if a team is up by some astronomical number the clock runs continuously except for time outs. I wouldn't place that number below 30 as there are time when a team can mount a comeback if the deficit is under 30.