For the xenial->bionic question, I had already implemented the workaround mentioned here to use Dpkg::Options::="--force-confdef" across all upgrade tests, which has been working fine. I can remove the workaround and try it if you are specifically interested in finding out whether it's necessary on the upgrade to bionic though.
For the xenial->bionic question, I had already implemented the workaround mentioned here to use Dpkg::Options: :="--force- confdef" across all upgrade tests, which has been working fine. I can remove the workaround and try it if you are specifically interested in finding out whether it's necessary on the upgrade to bionic though.