I've ridden the bike with the upside down lever, what I don't like about it.
The brake gets tighter when pulled off the center stand and weight put on the rear wheel.
also when ridding and putting pressure on the brake pedal, the brakes feel like they are out of round. I'm not sure why this is happening, maybe the cam shape isn't quite right? To me it feels as if the brake shoes are ridding up and down the cam.
A third problem- even though I tried to mimic the profile of the cam, it is not shaped quite right. The off shape keeps the brake from engaging solidly.
So, my conclusion is to remove the came and return the lever to the stock location.