***** Update *****
I now have the system booting into graphical mode. Here's what I found out in the
process:
I use the process as stated above on the stock Fedora 24 Mate Spin (kernel 4.5.5-300) to
build the system. However, on the "append" line of /boot/extlinux/extlinux.conf,
you do NOT need all the "dracut" parameters required to build the initramfs.
Rather, my append line simply looks like the following:
append ro root=UUID=4d70d307-a61d-4cda-9535-8a8849c262c2 cma=64M
That's it.