Mat,
1 quart for every 200 miles is excessive for an engine with 6500 miles on it. It should have been broken in long ago. Are you seeing evidence of
oil fouling on the spark plugs? If so, I'd think that running the engine on
synthetic with your ring and bore-hone set up was incorrect. Though some engines are fine this way most are not. I'm a big proponent of synthetics but have never had an engine that was built to tolerate them during break-in. This is something that you may want to discus with the engine's builder.
Steve