Did anyone's baby come home on human milk fortefier? if so did your insurance pay for it? both of my boys came home on 2 bottles goodstart 24 but one of them is not tolerating it (unexpellable gas) and was on HMF successfully in NICU...thankfully NICU switched him and gave us one box but that won't last long and it is $184/box!
Re: enfamil HMF
Gabe did HMF in the NICU. Have you tried fortifying with neosure? Gabe had no issue transitioning from HMF to neosure. He did it straight (2 bottles of neosure a day).
This is how to fortify with neosure, it is a small amount so it may not effect them like a straight bottle.
Breastmilk: Fortified (using NeoSure Advance Formula)
We'll miss you sweet Debbie Girl (4.21.12) and sweet Cindy Girl (8.9.12)

We couldn't fortify because LO had a bad reaction to the Neosure (milk protein intolerance), so we had to just push him on BM volume instead. However, as PP said, it works the same way as the HMF. My NICU used both but preferred adding the Neosure to BM over the HMF because it is commercially and readily available after discharge. So I would definitely look into this!
Is HMF liquid or powder? The only drawback to Neosure is that it is powder only. There is some research and controversy over using powders in the NICU because powder isn't sterile, etc. However, my NICU, a top level NICU, used it and obviously it isn't an issue now that you're home. (I was just curious if perhaps that's why your NICU put your LO on HMF instead . . . . )
HTH and that your pedi green lights the change! The Neosure makes BM 24 calories I believe, so it should work!