ETA for unicode combined char in Pango?

["Mathieu Pellerin" <nirvn asia gmail com>]

Greetings,

I was wondering if the Pango developers have an ETA on a
yet-to-be-supported feature that, lacking the proper technical term, I
would define as 'unicode combined char'.

For example, the unicode character U+17FE, a Khmer vowel. You can
reconstitute the vowel using two other unicode character (U+17C4 and
U+17C7) hence me labeling it 'unicode combined char'.

I'm not sure how it'd affect other languages, but for Khmer while it's
not critical, it would certainly be a time saver.

Matt