Chữ Nôm support

Apologies for taking this long to follow up. Harder issues tend to stay at the bottom, and I address issues last in, first out for convenience.

I've read w:en:Chữ_Nôm. That page also states that Chữ_Nôm is an almost script: Nôm was replaced by quốc ngữ (alphabetical Vietnamese) beginning in the 1920s and is now almost entirely obsolete. (quote from first paragraph).

Are you really, really, really sure you want to spend time on this? A user interface language is a lot of work, and you create it to have it actually used. Not having vi-hani would mean that you can still have texts in vi-hani, but with the currently used vi-Latn localisation, which all users are used to. I really think it might be a less optimal use of your time, esspecially since there are still over 20,000 messages to be translated in Vietnamese.