> please try to build extension modules with mismatching abi flags (pydebug is the
relevant one). Post your results for both mismatch cases.

Hum, you are claiming that there is a problem with mismatching abi flags but don't care to explain why or to demonstrate the problem, and asking instead that it should be proven by someone else running a test that you are right...

Anyway, you are mistaken. The cross-compilation of Android with 'pydebug' set, using a native interpreter built without 'pydebug' gives the following results:

The native interpreter:
[xavier@bilboquet python-native]$ ./python
Python 3.7.0a0 (default:879bde95a456+, Sep 13 2016, 18:59:47) 
[GCC 6.1.1 20160707] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> sys.abiflags
'm'

The Android interpreter built with this native interpreter:
root@generic_x86:/data/data/org.bitbucket.pyona # python
Python 3.7.0a0 (default:879bde95a456+, Sep 14 2016, 14:53:50) 
[GCC 4.2.1 Compatible Clang 3.8.243773 ] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys
>>> sys.abiflags
'dm'
>>> import _socket
>>> _socket.__file__
'/data/data/org.bitbucket.pyona/python/lib/python3.7/lib-dynload/_socket.cpython-37dm-i686-linux-android.so'