After opkg-update, opkg list-upgradable shows several packages that have updates. However the docs say:
Upgrading packages is generally not recommended for most users, because a typical system stores the base system in a read-only SquashFS partition. And while the upgrade process works just fine, it uses far more space than a default installation as the base packages are duplicated in the base SquashFS partition and the user JFFS2 partition.
So what's the recommended course of action with LEDE? Should I assume point releases will be frequent enough that upgrading packages mid-release should be reserved for security patches?
It depends from the size of your flash memory.
According to the wiki, that device should have around 29 MiB of free space in the flash memory, so you can probably update all you want.
You can check how much free space you have by writing df -h /
on ssh remote terminal or by going in Software page in Luci webinterface (System drop-down menu --> Software).
It seems like the wiki's info about that is assuming you don't have much space, which was true for older devices, but most newer ones aren't space-limited. Therefore I'm adding this to the wiki too.
I think that updating extra feed packages is rather safe, but it is more risky to update core packages as they are more tightly tied to each other and the kernel drivers. ( Like base-files, procd, ubox, ubus, firewall, dropbear, etc.)