Presumably the work you mention in relation to the change from the MySQL extension to the MySQLi extension can be done/completed regardless of what problems Adobe might cause in future releases (and it certainly seems that Adobe is very inconsiderate to its developers). When you say you are "waiting on adobe's next Dreamweaver release", do you mean before working on the update or before releasing it?
Dreamweaver users are used to having multiple versions or reverting to older versions to deal with problems caused or features removed following 'upgrades' etc.. I think if you released an update today (hypothetically), your users would be more than happy and totally understanding if it meant delaying upgrading to DW's next release (it's not very likely this would be necessary anyway). As it is, the MySQL extension is not just deprecated in the latest version of PHP (7) - it has been removed.
I imagine you have little problem knowing what code you need to generate with the DW extension; the challenge is in creating an automated means of generating it, bearing in mind a great many variables (and the odd spanner in the works from Adobe). It might be very useful for some of your existing users if you could provide a few examples of existing code generated by the extension and how it would ideally appear using MySQLi. Also, if new versions of files such as wa_appbuilder_php.php and wada_search.php are already updated, perhaps they could be distributed for users who would be happy to modify the existing code manually, before waiting until the full extension is available.