Here's my thinking. There is very little of a track record for E85 fueled, premix, 2 strokes. I will let someone else experiment. What I do know is that there have been problems getting petroleum based 2 stroke oil to dissolve in alcohol. However, fully synthetic, ester based oils seem to do better. In addition, there is an ongoing controversy as to whether ethanol has any inherent lubricity. Again, I'll let someone else figure that out. These issues are largely irrelevant with a 4 stroke, but in a 2 stroke where the alcohol will be coursing through the crankcase and that dissolved oil is all that keeps the engine from eating itself, I would not want to take chances.
If you do, have fun. I will watch and learn.
Here are the facts- E85 has less energy per pound (and less energy per gallon) than gasoline. What it does have is a much higher octane rating and the need for much less oxygen in order to fully combust. What this means is that you can run much higher compression (in a healthy engine) and reclaim some of the lost power. If you jet correctly- really richen it up, you can take advantage of that need for less O2. If you just richen, you may get close to the original power with gas, but not quite and fuel economy will be horrible. If you increase the compression enough and richen, you can make about 20% more power than gas. However, your fuel use will go up by way over 20%.
After all, the only way to make more power with a fuel with less energy content is to burn a lot more fuel in the same time.