Hi, I've a suggestion...
If possible I'd like to see bash, zsh and openvpn packages installed from the iso.
Why?
I use ProtonVPN and on a fresh install I'd like to use the vpn straightaway.

I find fish over-complex for my needs and zsh simpler to use and configure.
I can easily prevent history logging and change the TE prompt, and the in-built setup utility is convenient.

Non of my existing openvpn scripts will run without bash.

Of course - keeping the iso light is important - though I don't use evolution nor transmission-gtk, which I remove....

openvpn Flat size : 1.76MiB
bash Flat size : 9.52MiB
zsh Flat size : 19.7MiB

As a work around I use an existing Ghost system to
sudo pkg create -a -o /home/me/packages/All
and install from this local file the bash, zsh, and openvpn, hoping there are no conflicts.

You can create your own ISO with the packages you want. There's a program on the GhostBSD GitHub page It's called ghostbsd-build. Git clone the ghostbsd-build repo then go to the pkg folder and add the program you want by adding the program names to the already existing programs. Then build the ISO. It doesn't take long.
Either that or submit a feature request on the GhostBSD homepage

Hmm,
OK, the build process stops at the end with:

./build.sh: transmission-create: not found

The line in the file states

transmission-create -o ${iso}/${torrent} -t ${tracker1} -t ${tracker2} -t ${tracker3} ${isopath}

However, adding the package
transmission-utils
Gets the process to conclude with:

Creating torrent "/usr/local/ghostbsd-build/iso/GhostBSD-23.06.18.iso.torrent" ... done!

.
Thus the transmission-utils is required to create the .iso.torrent file.

However, the built non-torrent iso hangs within 15 seconds on installing ghostbsd right after the "masks" line.
There's something else required I think to build the iso...

Steve
I used the unstable build.
I have installed transmission-cli and rsync and git and transmission-utils.
I updated the ghostbsd-build repo with a 'git pull' before starting.
I copied the built non-torrent iso to the USB with:
dd if=/usr/local/ghostbsd-build/iso/GhostBSD-23.06.18.iso of=/dev/da0 bs=4m status=progress && sync