Hi !
Two big modifications have been merged into ProofreadPage trunk last week.
They will be deployed next week, Wednesday, October 31 with Mediawiki 1.21-wmf3 and are already live on beta server: http://en.wikisource.beta.wmflabs.org

The first one is the rewriting of the edition form of the index pages in PHP in order to decrease loading time and add new features like an help system. A description have be made in OldWikisource: https://wikisource.org/wiki/Wikisource:ProofreadPage/Improve_index_pages#Improvement_of_the_index_form .

In oder to add these new features (default value, help message...), this rewriting introduce a new configuration message for index pages based on one JSON array located in Mediawiki:Proofreadpage_index_data_config . JSON format have chosen because it's very extensible in order to add easily new features in the future. This message regroup Mediawiki:proofreadpage_index_attributes and Mediawiki:proofreadpage_js_attributes .
The use of this new configuration way is not required in order to have time to improve the configuration system in the future if there are any problem and to allow a smooth migration. Small wikis are invited to keep using the old configuration way.
This format is also described on oldWikisource: https://wikisource.org/wiki/Wikisource:ProofreadPage/Improve_index_pages#Improvement_of_the_index_form
A migration tool have been written in order to migrate easily: https://toolserver.org/~tpt/upgrade/config.php

The second change, more small, change the way of configuration of Index and Page namespaces: the configuration will not be done in Mediawiki:Proofreadpage_namespace and Mediawiki:Proofreadpage_index_namespace but directly in PHP configuration. The support of the new configuration system have already been added to Wikimedia's websites configuration so their might be no problem.
Description of the new configuration system: https://www.mediawiki.org/wiki/Extension:Proofread_Page#Namespaces

If you find bugs please report them in Bugzilla: https://bugzilla.wikimedia.org/enter_bug.cgi?component=ProofreadPage&product=MediaWiki%20extensions

Thomas ( User:Tpt )