Possible argp implementation questions regarding the use of <stdio.h>

As I mentioned when I e-mailed from outside the mailing list a while 
ago, I'm working on an very stripped down argp baremetal implementation 
that I would like to contribute to newlib at some point. As Corinna 
pointed out I don't want it to be GPLed so I've been writing an 
implementation from scratch that doesn't even depend on getopt.

I have a question regarding the use (or lack thereof) of <stdio.h>.

Context: For the target we support we can't use newlib's printing 
functions because we can't provide an implementation of all the required 
OS subroutines. This is due to working on a very limited target. This is 
all to say, our stripped down argp can't include <stdio.h>, and in the 
future I would like to contribute it to newlib in a way that doesn't 
require including <stdio.h>.

Question: From what I've been told by colleagues, newlib aims to be a 
very "drop-in" replacement for a regular stdlib. So I'm asking if it 
would be an issue to contribute my argp version that:
1. Already deviates from glibc's in the fact that it's a stripped-down 
version that doesn't implement all the features. And also deviates in 
small ways in certain features it does support.

2. Has an additional mechanism for the user to specify which printing 
function to use, instead of just including <stdio.h> and using the 
provided printing functions. With the goal of having wider support 
across baremetal targets.


Best regards,

Ignacio Vargas