It's been over a week now with a 20 lb on first, and a 25 lb on second. This is working pretty well for me, and it's 1000% better than stock. It takes off from a stop about the same as stock, but now instead of shifting early in the dead zone at 15 mph, it stays in first and starts ripping up to 20 mph.
I've learned that I can have a little influence on the shift point. If I stay hard on the gas it shifts about 21 mph, but if I roll off the gas a little it will shift early at about 18 or 19 mph, and the shift is smoother. Once in second, it stays there unless I get back down to about 15, where it down shifts to first.
Even though this didn't add any hp to my bike, it made it accelerate lot faster than before, because it allows it to stay in the power band more of the time.