I've thought about this a little more. I have had a lot of experience flying 15 size stunt airplanes. Dmeco Sport Wings, A-B All American, Cougar, A-B Trixter Profile, #5 Easy, Mackey Profile, etc. These are all a bit smaller than your airplane. They have weighed in the 17 - 19 oz range. With ST G20-15 diesel, I flew for a while with 9 x 4, which the diesel turns at @12,000. It was satisfactory. Later I went to an 8 x 4 which moved the engine up the power curve (review says peak HP at 15,000) and think the engine is happier. I flew on 55 to 57 ft lines, eye to eye. No problem at Tuscon at 2500 ft.
So, I think 11,000 on a 9 x 4 would be disappointing, particularly at your altitude. 24 - 25 oz, for your size airplane,sounds about right to me. Also, I don't think you will be able to fly on long lines.
Thank you for this helpful information. It's solid food for thought, based on your experiences. Magnum also recommends an 8X4 prop. I also agree with the prop proposal. As for weight, I think I can keep it light by careful selection of wood and sizes during construction.
Weight is another thing though. I've been taught that comparing to a known stunter usually works out OK. Since here where I live, the altitude is high, we relate to a 38 ounce Nobler as a standard to shoot for.
A Nobler, at 38 oz's gives a loading at just under 14 sq inches per ounce. I like to use the square inches/weight instead of the weight/square inches (times) 144 (the number of square inches in a square foot) which in the case of the above Nobler, is 10.325 oz's per sq. ft, but, I'll use the latter in this case.
The lil' Elle, would be slightly less than 9.5 ounces per square ft at a total weight of 25 oz's, making the wing loading better than that very light Nobler above.
So, a wing loading matching the light Nobler would be achieved with 27 1/4 ounces of total weight with the new design.
Nowadays, every where else, a normal Nobler is figured to be really good if the total weight is 42 oz's, which makes a wing loading of just under 11 1/2 oz's per sq ft.
So, the weight that matches for this new design is slightly more than 30 oz's.
Of course the newer airfoil should be able to carry more of a loading than the thinner Nobler AF, so I feel that somewhere between 25 and a max of 32 ounces should work out, of course lighter should be better.
The line legnth as you've suggested, will likely be under 60 feet.
It's going to be fun, I think, and thank you for your interest and helpful contributions.