Thanks, but that isn't really my question. Yes, we've looked at completely overhauling our existing imaging infrastructure to avoid a bug with DHCP autoconfiguration edge cases. That may be the route we go, but that is not a trivial amount of work. The debian-installer FAQ declares that it was designed with modularity and support for edge cases, as well as giving more control to more experienced users. What I'm trying to do should not be complicated. It's literally just executing another script before attempting to download a debconf file to make sure it has an IP address from the DHCP server. I wouldn't even need to do that if network autoconfig didn't forcibly release all existing DHCP leases on a system when it starts.