Get separate Whonix-Gateway and Whonix-Workstation .ovas?

Separate Whonix-Gateway and Whonix-Workstation ovas are at this time not offered for download. It’s not planned at this time either.


Simple: You could just import the unified ova and then export any VM you like. It’s a standard VirtualBox feature and unspecific to Whonix.


Difficult:
Building from source code:

Even when you build from source code, by default a unified ova will be built. By default, build-steps.d/5200_prepare-release runs packages/kicksecure/developer-meta-files/usr/bin/dm-prepare-release and its function virtualbox_export creates a unified ova.

VirtualBox VMs are created in folder /home/dm-vbox-temp under account dm-vbox-temp. If you can mange to export it from there, that would work too.

It might be possible to set vm_multiple=false.

sudo mkdir -p /etc/buildconfig-dist.d
echo "vm_multiple=false" | tee /etc/buildconfig-dist.d/50_user.conf

Untested.