As I replied in, boot failure, the issue with /boot filling up was resolved, but the result was worse, with the boot hanging. This is now the subject of bug report bug 12851.
Fresh installing core 166 on arm7hl then upgrading it to core 167 testing is a time-consuming process, which I have not done on all of the many testing builds. If anyone has done so with the latest build 0000-1bd22b04, then they should be able to provide a further report.