[BMERDOC]

I never explained that the brakes needed to be locked down either. I have been under the assumption that most would sub out the alignment. I haven't explained at home alignment because I have had a machine at my disposal for years now and haven't had to perform an alignment in that manner. As far as good alignment shops, I think its because you toss the key to them and tell them to align it. Leaving them to their own devices can cause them to be lazy. You would have to search out a shop that would be willing to work with you on the specs.
In short, the brakes need to be locked so that the wheels don't move as you complete the caster sweep. The lock tool is picturd in a previous post. A steering lock is also shown to keep the steering wheel straight as toe is adjusted.