This is my last try, promise. just hear me out.
There is a core function named switch_to_blog() on /wp-includes/ms-blog.php
the comment says :
This function is useful if you need to pull posts, or other information,
from other blogs. You can switch back afterwards using restore_current_blog().
Things that aren’t switched:
– autoloaded options. See #14992
– plugins. See #14941
It’s really useful to use on p2p, if I’m trying to connect a post_type from one blog to another, it does not have to be reciprocal and has new posts creation.
p2p can get the blog id and post type on p2p_register_connection_type() and save post_ID from one blog, and another from the other blog on the table for connections, maybe the link and title as connection fields to avoid overload and I think the rest is the same.
It’ll be very considerate of you to just look at this possibility, I’m really trying to not re-inventing this particular great wheel!