You ship moc with xorg but without moc-ffmpeg-plugin. Allthough it's not a big deal for the well informed user to install it, it doesn't make much sense not to privide it on the ISO, given it's size:
# ls -la /var/cache/apt/archives/moc*
-rw-r--r-- 1 root root 251160 Sep 2 12:06 /var/cache/apt/archives/moc_1%3a2.5.0-1_amd64.deb
-rw-r--r-- 1 root root 34012 Sep 2 12:06 /var/cache/apt/archives/moc-ffmpeg-plugin_1%3a2.5.0-1_amd64.deb
An other package I'd recommend is roxterm. I used to install konsole as VT (although I am exclusivly using fluxbox) due to its fine grained profile setting features. But with my newest install on my laptop I saw 156 dependencies to come in with konsole. So I found (recommended from someone @ debianforum.de) roxterm.
It seams it has matured over time and for my usecase it is able to replace konsole with ony a bunch of packages a dependencies:
# LANG=C apt-cache depends roxterm
roxterm
Depends: roxterm-gtk3
# LANG=C apt-cache depends roxterm-gtk3
roxterm-gtk3
Depends: librsvg2-common
Depends: roxterm-common
Depends: libc6
Depends: libdbus-1-3
Depends: libdbus-glib-1-2
Depends: libgdk-pixbuf2.0-0
Depends: libglib2.0-0
Depends: libgtk-3-0
Depends: libice6
Depends: libpango-1.0-0
Depends: libsm6
Depends: libvte-2.90-9
Depends: libx11-6
Conflicts: roxterm-gtk2
I understand you use xorg-iso as a basis for internals test and you want to keep it small. Maybe we could create a meat-package with some extra packages meant to enhance the xorg-iso for those who use it as a real Desktop.
BTW:
I now got a hint how to configure lightdm to my needs (yes, we disagree about the security implications):
If like the greater to show the latest user who logged in you only have to edit:
/etc/lightdm/lightdm.conf
greeter-hide-users=false
So no more kdm for me.
And while I'm at it I still feel we should add a "howto set your fonts" to the xorg-iso. User installing this flavor will - sooner or later - pick packages based on different toolkits (like I do, I try to avoid too much dependencies, but at a suitable moment Idgas). If you (convbsd) are willing to add such a howto to the ISO, I am willing to write one.