More on inheritance and foreign keys

Hi,after starting this thread 
http://archives.postgresql.org/pgsql-hackers/2006-05/msg00222.php, I thought 
I'd finally go for making foreign keys my own way instead of trying to patch 
PostgreSQL. However, I've realized that managing foreign keys with my own 
PL/SQL or C function isn't possible as I need DEFERRED checks which are 
currently only available for foreign keys.
The solution to the foreign key problem seems easy if I modify PostgreSQL 
implementation and take off the ONLY word from the SELECT query, but it's not 
an option for me, as I'm developing a library, not an application. I'd like 
many people could use it.
Would it be acceptable if one could add the INHERIT word when creating 
foreign keys, in order to change the SELECT behaviour? Are there other 
solutions to this problem?
Thanks.