Obviously, I'm glad you got your cargo to where it needed to go on time, but I'm surprised you got a 23,000 foot block or even thought you needed it.
I used to plan and fly large military movement of packages of multiple large and fighter aircraft across the country and oceans and it took a lot of planning and coordination to get those ALTRVs approved.
My biggest question is why you would even tie up that much airspace when you didn't need to. Obviously you generally knew where the max altitude was going to be at level off weight (you said FL380). If your FMS is like mine, it'll spit out MAX/RECMND altitudes. Even if you went up every time it clicked over to another 100 foot, you'd only have to get a 2,000-4,000 block at a time and as the pilots neared the top of the current block, they just ask for another 2,000 foot block above the one they're in.
Just seems like a waste of precious airspace. Like I said, I'm glad your mission got off okay, but I wonder if there were any other "LIFEFLIGHTS" that couldn't make it because you had needlessly blocked off half of the useable altitudes over half the country.