I want to install Mojave on a second partition of my MBP(9,1), but for a variety of reasons the drive is still AFPS and I DO NOT want to change it at this time. I'd normally only install on a secondary machine, but I'm a bit "up a creek" as my only other potentially compatible computer(my MP 5,1) doesn't have a metal GPU(and I don't want to change it to one as SL compatibility is critical to its current use). So, has Apple now made AFPS a requirement? If not, how can I avoid a format in place? (if not, it may be time for an Optibay and a small secondary SSD).