> [...] I proposed to add to the fontenc an information, which Unicode
> range is to be loaded for this fontencoding. To clarify this, here
> an example:
> if we have code like the following:
> \usepackage[utf8]{inputenc}
> \usepackage[T2A]{fontenc}
> the file t2aenc.def could contain a line like:
> \FontencUnicodeRange{"400-"4FF}
> and \AtBeginDocument UTF-8 sequences would only be loaded for the
> ranges given by the fontencodings, thus taking the need from the user
> to decide by himself, which sequences to load. In case no UTF-8 is
> needed, the \FontencUnicodeRange's are ignored.
> Of course, the fontencoding->Unicode-Range mappings could also be in
> some extra file, thus removing the need to change the existing
> fontencodings.

I like this idea.  It is really only a matter of taste whether we
have a new unicode.cfg file or \FontencUnicodeRange macros directly
in the fontenc files.