To add to this, I looked at PC10 when I added a new BIOS set a few years back and it was.. quite honestly a disaster with structure that made little sense.
There are things you can fix, and there are things you rip out and start completely over with. PC10 is the latter. I'd love to see 10 slot support, but it's not going to happen unless someone gets a lot of time and interest in doing the driver over correctly first.