[pmwiki-users] getting $EditFunctions very last position

[SteP]

My php code changes a page permissions in a way that can make a page unreadable to the current user. 
My code is called as an edit function which is appended to $EditFunctions at the very end of config.php. 
It's placed at the very end in order to avoid making the page unreadable before all other edit functions 
have had their turn at processing and saving the page.

I don't know how to ensure that my function is really the last one of the chain. I noticed that pagelist.php 
appends PostPageIndex() to $EditFunctions after config.php processing, hence after my edit function. This 
results in two php warnings in circumstances when pmwiki.php is setting up its own html redirect after my 
edit function has changed page permissions.

Is there a way in PmWiki 2.2.16  to reserve the very end position of $EditFunctions for my edit function?

Would upgrading to version 2.2.17 open up a solution? I read about the post-configuration features 
introduced in that version, but I'm not familiar with it, yet.

Thanks in advance.