Added a note: "Note that this is a rather complex mechanism and this section errs on the side
of explicitness. Users are encouraged to find an example and duplicate it if
they don't feel the need to understand the subtlety. The builtin dialect
provides some relatively simple examples."
I struggled with the level to write it. Open to revisions!
Added a note. The caveats are not something that regular use should ever hit. More of a cautionary tale to avoid pushing the edges of the abstraction.