I do both, stugots. I offer the same short price on each horse in a race and try to remove the offer while the result is still a guess if nobody has taken the bait. I also back leaders in running if they look to be going comfortably. Favourites that lead are a sure source of income overall.
I think your method above is a good one. I find with harness racing it is a good ploy to lay badly drawn second or third favs and attempt to green up when they drift a point or so in the run.