An interesting idea about penalties. Obviously, the point is to get owners to put pressure on their trainers. But it will also pretty clearly punish the innocent, unless the assumption is that the trainer uses the whatever on all the horses.

If you do make this assumption, then why would you let any of the horses run at all - weight addition or no? It might have that effect anyway - how many owners would accept a point handicap. They might move their horses, but that just puts the next 20 in line for the handicap. So, just go ahead and say the trainer can't run any horses for a couple of months.