I've abstained from saying anything yet because you're gaining ground and learning the ropes of this modding thing, and I didn't want to somehow... dissuade you from going at it over and over again. So bear that in mind when I say this:
As some of us have noticed when it comes to grass tampering, there are two main issues aside of taste one has to take into account. One, as Zwerk mentioned earlier, is density. Sure, things look lush, but most people don't have high-end PC's to endure such. Now, you say you have no issues with that, but you should try these settings in an actual module, rather than a test area. "The Aielund Saga 1: Nature abhors a vacuum" has some very large, populated areas made with TNO. I am guessing even your rig may suffer a drastic FPS drop under such circumstances. Add to that this is just a grass modification. If by any chance you choose to change any other textures to a higher resolution for definition, it all keeps adding up. Imagine playing amidst high-poly creatures and placeables with large textures aside of the grass modification. It can all slow systems radically.
Second, you're not taking visibility into account. Tall grass looks great, but in actual gameplay, it turns out to be a very big nuisance. Remember modules are populated both by creatures and placeables. Particularly "remains" bags are hard to spot in such lush environments. The same happens to corpses and small placeables. Now, take lighting into consideration as well. How does your grass look at night, at dawn, at twilight? Does it look the same under most conditions? Does it offer even less visibility when it's dark? Some modules don't allow for passage of time, and remain dark all the time. Lord of Terror's forest comes to mind, which is hell if you have lush vegetation mixed with unmoving placeables like corpses, rocks, chests, etc.
Of course, this is all dependent on your goal. If you're making this solely for yourself and you don't care about all of these variations, then more power to you! If you're willing to share it "as is", same thing; let the end user modify it as it fits them, or deal with it if they have no knowledge of how to do so. Finally, if your objective is primarily to share it and for it to be functional, there's still things to test and take into consideration.
I reiterate I don't mean to bring you down or otherwise hamper your efforts. I just share what I have realized myself over the years modding the game as well. Good luck!
