Can't preserve extended partitions?

[mod+linux-fai at std.com]

Why can't we preserve extended partitions with
setup_harddisks?  I understand that extended
partitions are arranged as a linked-list with
one pointing to the next, and I can see how
it might be easy to screw that up.

But if I have a disk with three primary
partitions and five extended partitions and
I simply want to delete the third primary
and extend the second to use that newly
available space, why should I have to lose
all my extended partitions?