I think that having the provisions to shift the balance aft is a good idea. I had to drill out some lead as my plane was very nose heavy on first flight. The balance is about 1 and 1/8 back from the starting point. My plane requires less up elevator to keep it in the air and now it can fly inverted. Before, inverted flight was very scary and almost all down to just hold it level. I'll get an exact measurement of where the balance is and get it posted. I think this is the furthest aft I would go. In some turbulent/choppy air and wind, I would put 2 oz in the nose to gain some stability for landing.
I flew it this weekend at Bakersfield CA, Lake Ming. Burned 6 tanks of fuel with no problems. Altitude was 520 feet. Lots of power with the OS 55 and at 7 lbs, the plane leaped off the water in 20-30 feet. I was able to slow it down to a crawl and just at the end, balloon the nose up and the plane would just about stop and plop onto the water then slide 5 to 10 feet. Coolest thing I've ever seen. Next time I need to get a video of it. Check out the plane on some earlier pages on this link to see what it looks like and some mods on the tail and servo installation for those who are building one. PREDMECH, WES