Yumex force i386 architecture option removed

[Jay Cliburn]

I maintain a howto over at fedoraforum that deals peripherally with
installing firefox.i386 on an FC5 x86_64 system using Fedora repos.  The
main purpose of the howto is to provide instructions for installing
Flash and Sun Java plugin capability in Firefox under x86_64, but to do
that, of course, you first need firefox.i386.  The procedure is here:
http://forums.fedoraforum.org/showthread.php?t=102143

Several weeks ago I ran across a reference to the "Force i386
architecture" checkbox in yumex, which, as the option implies,
configures yumex to pull i386 packages into x86_64 for those who need to
do that.  I don't use yumex, but I looked into it at the time and the
option significantly simplified the process of installing firefox.i386
on an x86_64 system, so I added it as an optional procedure in the
howto.

In the last 24 hours, someone using the howto reported the absence of
the yumex "Force i386 architecture," so I looked for myself and sure
enough, it's gone in the current release of yumex.  Some digging turned
up this:
http://linux.rasmil.dk/cms/modules/wordpress/2006/04/24/yum-extender-and-i386x86_64-troubles/

In this link, the yumex developer reports being advised by one Jeremy
Katz of the inherent dangers of using the force i386 option, alluding to
an "update nightmare" by so doing.

My question is this: How is using the yumex "Force i386 architecture"
more dangerous than using i386 repos from the yum command line?

Jay