As some of you are already ware of, LuaTeX can load hyphenation patterns
dynamically (i.e. in non-initex mode) and thus hyphenation patterns need
not to be loaded in the format, actually what gets stored in the format
is the string representation of the patterns and it gets re-evaluated at
format load time, so loading many patterns in the format results in too
much startup delay (3 seconds on my system) for no good reason.
Trying to fix this for Babel, i.e. hyphenation patterns are only loaded
when requested, I patched hyphen.cfg file to do so when running under
LuaTeX. It seems to work, as far as my tests go, except that would need
to explicitly select a language or there will be now hyphenations i.e.
Bebel don't seem to load any language by default (unlike plain TeX), and
I'm not sure how to handle this.
Patch is attached for your comments.
Arabic localiser and member of Arabeyes.org team
Free font developer