Thank you for posting the Policy.
Read through it. Its nice when an AHJ put thing in writing and also applies some common sense as well.
As far as a breaker lock goes I do not see where it is required until you comply with R314.7 Fire alarm systems. I did not read where it required for your installation. please feel free to point out, I miss thing at times.
I did not read where a dedicated circuit is required as well i see it as optional for your installation. I do see how it would apply to R314.7 Fire alarm systems. I did read where they did not want it on a GFCI circuit and that makes sense. So if for some reason it (smoke detector outlet) was tapped from a branch circuit that has a combination ARC/GFCI device than it would be in violation.
As far as being a a good idea to do so, I get it. Its not an expensive item to install other than the dedicated feed to the first location and the branch circuit over current device. After that they have to interconnected anyway. Plus its bid into every job and all on the same playing field. The KISS rule applys ( keep it simple silly). If R314.7 Fire alarm systems, i would think it would have to be red in color however that may or may not apply to your area.
I do like the way they defined existing dwelling applications. I have read here on this site where that has been an issue when doing other work.
Thanks again for some good read and information.