Truth!!!
I'm not gonna read your entire post - I'm just going by the title, okay?
If you look in my fuel log, you'll see that I tried running partial fills for a while - albeit on a near empty tank - and my FE dropped like a rock!
I haven't tried partial fills on a near full tank yet - but I can tell you that running my tank low gave me mileage for sh!t, if that helps...
In other word(s) - FAIL!!!
Now, I'll read your post...