To be completely clear about the decision that Ian asked the technical committee to overrule:
In all debootstrap versions since 1.0.102, merged /usr is the default (for all variants except --variant=buildd). This means that new installations of Debian buster using debian-installer will have merged /usr. Do the debian-installer and debootstrap maintainers think this should continue to be true for the buster release? (Sorry, I should have made this the only question in a message, and not mentioned side issues in the same message.) Thanks, smcv