One improvement in this case would be automatically listing bugs with "ftbfs" tag on update_excuses.
This would help assessing the current state of the package quickly and would also help recording observations in the bug, for example when packaging in Debian stopped providing binary packages for a given set of architectures and the package is waiting for removals in Ubuntu.
Looking at britney's code it seems a script is needed to collect the ftbfs bugs from Launchpad and britney could load them like the "block-proposed" bugs but existing "ftbfs" bugs should not block migration just provide explanation for packages blocked due to missing binaries.
One improvement in this case would be automatically listing bugs with "ftbfs" tag on update_excuses.
This would help assessing the current state of the package quickly and would also help recording observations in the bug, for example when packaging in Debian stopped providing binary packages for a given set of architectures and the package is waiting for removals in Ubuntu.
Looking at britney's code it seems a script is needed to collect the ftbfs bugs from Launchpad and britney could load them like the "block-proposed" bugs but existing "ftbfs" bugs should not block migration just provide explanation for packages blocked due to missing binaries.