Unattended install: Guest OS type

[Technologov]

One outcome of my research paper a decade ago on unattended install, is that it requires a very specific Guest OS type.
Guest OS type *has* to become more granular.

Unattended Guest OS Install - Research Paper
viewtopic.php?f=10&t=46816&p=211275#p211275

Unattended Guest OS Install - vbox-unattended
viewtopic.php?f=10&t=67710&p=320651#p320651

I.e. not just "Red Hat (64-bit)", but more like "Red Hat Enterprise Linux 3 (64-bit)".
Both hardware is also different for different OS types. e.g. RHEL3 requires an IDE hard drive.
..and the script is very specific to an O.S. version.

For now, RHEL3 doesn't seem to work as unattended install guest OS. It says "unregonized guest OS type 3" ...
How is this implemented now ?