How do you set additional fields in the release file with apt-ftparchive?

The command apt-config's man page shows that it can be used to set these variables, with a --option option.

Unfortunately the options do not stick, which renders the setting them in apt-config absolutely pointless. (There probably is a reason, I just don't know enough to see it yet.)

Luckily, this --option option also works on apt-ftparchive, I had just overlooked that section of the man page:

   -o, --option
       Set a Configuration Option; This will set an arbitrary configuration option. 
       The syntax is -o Foo::Bar=bar.  
       -o and --option can be used multiple times to set different options.

So the full command line was:

user@server:/srv/repo/dists/ascii$ apt-ftparchive \
  -o APT::FTPArchive::Release::Origin="Devuan" \
  -o APT::FTPArchive::Release::Label="Devuan" \
  -o APT::FTPArchive::Release::Suite="stable" \
  -o APT::FTPArchive::Release::Version="2.0" \
  -o APT::FTPArchive::Release::Codename="ascii" \
  -o APT::FTPArchive::Release::Architectures="armhf" \
  -o APT::FTPArchive::Release::Components="main" \
  release . > Release