Just in case it is of use to others, I just updated http://www.nexusmods.com/skyrim/mods/57191, adding functions to read private values from any INI file.

This functionality is distinct from SKSE Utility script INI functions, which can only read INI values defined by Bethesda and loaded by Skyrim. My function instead forwards to Windows GetPrivateProfileStringA.

In effect, this will allow modders to create custom values in their own MyModName.INI file and have the bool/init/float/string values accessible to Papyrus.