linda mar wrote ...

When trimming swords, sometimes I can't quite get to the base of the stem,
and end up leaving about 1" or so of the stub left, which ...

What happens, as the plant gets older, is that the new growth from the
center forces the old growth (and old prune scars) outward and downward so
that, eventually, the stubs of the outer leaves end up horizontal.
Typically, the build-up of sediment and detritus (at least in the wild)
covers it, roots emerge, and the crown of the plant is raised to a higher
position.