We are AKV and SSR owners, and I forgot to try to book BLT right at 7 months, missing by about a week. I had, however, booked the last three nights of our trip in Kidani savanna view (bc didn't have enough AKV points to book whole trip) at around 10 months, and I'm glad I did! I was able to get the first four nights using our SSR points, but I wouldn't have been able to get the full week at that time, had I needed to.
It's OK -- BLT is GREAT with a 2-year-old, for convenience, but she will really love the animals at AKV. What I really want, though, is VGF to open up, and to change our reservation to there.