Peter Kadau answered a question from Jonathon McKitrick about getting rid of your boot manager, if you just have DragonFly:

boot0cfg -o noupdate -s 1 -t 0 -B ad0

Matt Dillon followed up on the topic mentioning that the ‘Dangerously Dedicated’ mode from the old FreeBSD installer is probably no longer worthwhile, and may even cause problems.