Normally a feature like this requires documentation in a manual as
well as code to implement it.
Can you elaborate on what changes are needed in which manual?
The code is already implemented i.e. the foundations to support these scripts are already there,
someone just needs to take their time and extend this support to a specific script, and I am doing
exactly that. This is nothing more than some grunt work.
This is what a typical patch for adding a script in Emacs looks like:
1. A one line entry in etc/NEWS announcing the support of the script and its language environment.
2. A one line greeting in the language/script which is added in etc/HELLO (optional)
3. A one line entry in script-representative-chars in lisp/international/fontset.el so that Emacs can select an appropriate font for it.
4. Adding the script name in setup-default-fontset in lisp/international/fontset.el
5. Defining a language environment for the script in the lisp/language/*.el files which includes the following entries:
its charset (usually unicode), its coding-system (usually utf-8), its coding-priority (usually utf-8), its input-method, its sample text (the same text which is added in etc/HELLO),
a one line documentation usually in the following template: "foo language and its script bar are supported in this language environment."
6. Adding composition rules for the script (optional, only needed for complex scripts)
7. Adding an input-method for the script in lisp/leim/quail/*.el files
Adding one of these patches does not mean introducing any significant or breaking changes.
All the heavy lifting functions or programs were implemented earlier.
We already parse all of the information from unicode so Emacs knows about these characters,
composite.el and harfbuzz take care of composition and quail takes care of input-methods.
The average size of my patches appears to be around 126 lines with the input method and 36 lines without the input-method,
which is a given since input method is needed to be defined for nearly every key on the keyboard.
I have added around 27 scripts since May of this year.
My point is that when Unicode incorporates scripts that aren't and
never were used very much, and were developed for PR motives,
incorporation into Unicode is not by itself a reason to add support
into Emacs
These scripts were not developed for "PR motives", they were developed to serve the needs of the community.
For example this what was said by the inventor of the Wancho script[1]
"I found out that it was not possible to translate the language as it
did not capture all of its sounds. So I started researching on phonetics
of the language," Losu said.
It is necessary for Unicode to support them because this is not the age of pen and paper where the only thing limiting you to write any script for communication is... you.
For computers this is not possible therefore efforts should be made to rectify this both at the Unicode level and the application level.
I don't speak either Urdu or Hindi, but I've read that Urdu has a lot
of vocabulary derived from Persian or Arabic. With such a difference,
they are not "virtually the same."
Urdu and Hindi have virtually the same grammar, having some different vocabulary does not make it
a different language. Hindi and Urdu are regarded as two different registers of the same language.