In terms of searching for earthquakes, I have been doing this for the outside world
for 12 years and have only been asked to use FE regions in two cases that I
can recall. The FE region is a convenient geographical name, however, it may
be asking a bit much for a predictor to give the FE number especially if they are
not acquainted with the minutiae of seismic regionalization and catalogs. Perhaps
as a option.