First of all, great book, thank you for that!
Second, page 212, I find that using a deathfloor or not makes no difference: the particles render where they are needed and seen, i.e, on top of the deathfloor.
That being said, I think the inclusion of a use case for that feature is a good thing, so feel free to keep it in, but maybe change the example to somewhere where it genuinely makes a difference.