Why would anyone in the right mind want to create 31 bootable partitions?
Probably 31 is too much, but the current limitation of four partitions is a problem. For example, I have six partitions on my 5.1G hard disk. I have an old version of MS-DOS, Windows 95, Solaris x86, another Windows 95 partition for programs downloaded from web, some empty space to test Partition Manager, and an Extended DOS partition. When I boot from DOS or Windows 95 I can see two partitions: one, from which I have booted and an extended partition with my files and programs. In addition, it is now common to have several OS, such as Windows 95/98, Windows NT, and various flavors of Linux in order to develop crossplatform applications.