A related question: If I rebuild the kernel and modules using the
defaults for "make xconfig", i.e. the default configuration settings,
should the new kernel and modules be the same as those from the
generic RH kernel? Or at least nearly the same? If not, could I get a
copy of the RH .config file and try building the kernel from that to
see if the problem persists? At this point I see no reason why my
"custom" kernel should be significantly different from the generic RH
kernel, especially with respect to the operation of the X-server, and
in particular the PS/2 mouse.

It sounds like your config files for X have become set incorrectly.
You can run mouseconfig and the re-run Xconfigurator. This should
detect your mouse and reset XF86Config to the proper values for your
mouse. If this does not solve the issue, then you can reopen the bug.

MetroX use a completely different config file so that could explain
why it works and XFree does not.

The problem cannot be with the configuration files because if I reboot
using the RH generic kernel, without changing the X configuration
(either for XFree86 or Accelerated-X), then the X-server/mouse works
correctly (with either). At this point I'm fairly sure that it is
somehow related to the kernel/modules since nothing else is being
changed when I reboot to one or the other kernel version. I probably
would not have contacted you with this "anomaly" except for the fact
that it is showing up with two substantially different X-servers
(XFree86 and Accelerated-X), and I think I've checked out most of the
more obvious possible causes. What is bothering me is that I cannot
build a custom kernel, even with the "default" configuration, and then
get the X-server to work correctly with that kernel. It is certainly
not in your interest to help me solve problems related to my "custom"
kernel builds, but on the other hand I'm reasonably convinced that
there may be more to this than just my blundering. Either way, is it
possible for me to get a copy of the .config file used to compile the
RH generic kernel, or is the default-generated .config file the same
as that?

I found the problem, or at least a fix. The problem appears to be with
the mouse driver [linux/drivers/char/psaux.c] where the constant
INITIALIZE_DEVICE needed to be set. As distributed by RH, it is NOT
set in the source file; the line is commented out. This brings up an
interesting question: Is the mouse initialized with the generic RH
kernel (the xconfig default compiles the driver into the kernel)? If
so, then perhaps the distributed source code should have the line
uncommmented?

This is being assigned to a developer for further review.

Further information for you, possibly confirming the mouse
initialization issue. If I boot up using the generic RH kernel and run
the Accelerated-X (or XF86_3DLabs) server, it works fine. However,
anytime after I've run the Metro-X server the other two servers fail
to work correctly with the mouse. Recall that the Metro-X server works
correctly with or without mouse initialization. Apparently, it would
be necessary to somehow reinitialize the mouse after using Metro-X in
order for the other two servers to work correctly. Most importantly,
this is true for even the generic RH kernel, not just the rebuilt
ones.

I am unable to reproduce this problem. The configuration RH used for
the generic kernel is availavle in arch/i386/defconfig in the kernel
source tree.

Metro X is not a supported product for 5.2 - you will need to contact
Metro to get support on that issue.