Yes, that's what "limitation" means.
There are 2 ways around this. One slightly decreases quality, and the other is an ugly hack.
1) You could optimize your lens flare. Get rid of the glows that are almost unnoticeable and leave the obvious ones until you have 10 glows and 10 textures. Then, use the same texture for glows that look similar enough to be indistinguishable. You'll need to get down to 10 glows and 6 textures but it should look OK.
2) This is a horrible suggestion and FREDders will hate you for it but you could use two separate stars. Get rid of three of the textures- I know you can do that- so you have 12 textures and 15 glows. Take the first 6 textures and (anywhere between 5 and 10) glows and leave them on the SunWhite that you have already. Then take the remaining textures and glows, and put them on a new invisible star entry (by invisible, I mean use a blank texture and no glare). The result should be identical to the effect you have now, except that it works. FREDders would have to place the two stars in the same location which makes this nonintuitive and less than ideal.
