Many fixes have been applied, and the code has been "stressed" and seem to work fine. Any possible scenario tested? I've try to cover in short all the possible, but of course it is required "more stress" to be sure that there are no bugs, and so if there is any brave around that like to test and in case report problems on the new 2.4.0-dev would be really appreciated.
Short how to use, that need to be translated into a new detailed Install Help Page
Since 2.4.0 release it is mandatory:
users can register into phpBB OR WordPress, you have to choose, it is not possible anymore to let register users both in WP and phpBB. It is possible to change and switch to one or other way anytime.
users can update their email, ONLY in WordPress profile OR phpBB profile.
If you leave users update their email and register into phpBB, then you'll have to take care of the fact that wordpress users DO NOT need to be allowed update their email and register in Wordpress.
If you let users register in phpBB, setup into phpBB ACP options to do not allow users re-use email or usernames for different accounts.
If you leave users update email and register in WordPress, then you have to avoid the same in phpBB, and to do this, just go to
ACP -> TAB System -> User Control Panel -> click into Profile -> Edit account settings, click into Disable to disable the user's account settings module. Then the Edit account settings , where it is possible to update user's email and password in phpBB ucp will not be accessible (while all the rest of phpBB profile options will be still available to phpBB users). Disable new registrations in phpBB, and you're up and running.
Based on this, someone could choose to hash passwords in phpBB way or WordPress way. Hints are on same option, into the integration plugin admin page. phpBB way used until now, and it is the default.
Default page-forum.php for the iframe mode has been updated, because the user ID1 in WP and UID2 in phpBB are not linked anymore, so a fix for this user, whenever he goes to navigate the forum in iframe mode, has been necessary. The old one will work fine for all users, but not for UID1 WP & UID2 phpBB, or they will fall into the "famous refresh loop" while visiting wp page-forum as logged in phpBB or WP.
new 2.4.0-dev03 release
Please add here in reply and bug found, reporting: environment, running plugins, and steps to reproduce the issue