Why would you want to ignore update.conf? It purpose is to allow you to recover
from the distribution of faulty config files.
"Imagine what would happen if you made a mistake in the configuration, i.e. a
syntax error which got distributed to every host. Now all the hosts would be
unable to run cfengine, and thereafter unable to download a corrected
configuration file. The whole setup would be broken. To prevent this kind of
accident, a separate configuration file is used to copy the files and binaries
to each host. This configuration should be simple, and should almost never be
edited: they key word here is reliability."
http://www.cfengine.org/docs/cfengine-Tutorial.html#Building%20a%20distributed%2
0configuration