I feel like someone oughta make a product that is a horizontal dropout that bolts into vertical drops, such that the horizontal dropout (or track end) sits just below the end of the vertical one. It could be a single, machined piece of metal. It would raise the back end of the bike up a little and make the rear wheel be much farther from the bridge, but it would be for fixed-gear conversions, so a rear brake wouldn't matter.
Does this make sense? Is there some obvious flaw to this idea that I'm not thinking of?