#+STARTUP: showNlevels
This tells org to expand N levels at startup, but it only partially
unfolds headings, so show2levels gets you:
* A [...]
** X [...]
** Y [...]
** Z [...]
Instead of (what I think is expected):
* A
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do
eiusmod tempor incididunt ut labore et dolore magna aliqua.
** X [...]
** Y [...]
** Z [...]
Perhaps this should be upstreamed?