Flap mode (“TOO LOW FLAPS” mode 4B) is inhibited to avoid nuisance warning in case of landing with flaps setting reduced. The normal landing flaps configurations in the software depend on the type.
To be precise, it is a basic GPWS function (modes 4A & 4B).
The enhanced function (EGPWS) provides terrain awareness by means of a specific algorithm, based on a worldwide terrain database, GPS, air data and radio altitude. If the airport where you'll land is not in the data base you should inhibit the enhanced function, again to avoid nuisance warning, but still you have the basic functions (modes 1-5)