Although we haven’t released an update in seven months, I make changes to the code every day. You can check by yourself going to our GitHub repository here [1] for the last couple of weeks I have been fixing a ton of bugs and adding more and more features as you can see in this pull-request [2] which at the moment of writing this comment contains more than sixty-five changes. Everyone is free to download the development version of the plugin at any time from here [3] this will get you all the updates that I push to the repository every day.
Regarding the issues that you had after you updated your site to the latest version of WordPress, it is hard to tell where the root of the issue is. The plugin has a lot of code. What I can tell you for sure is that for the last 3 years that I have been maintaining the code I have removed every call to the database. The plugin stores all its settings, security logs, cache and additional data into plain text files at “/wp-content/uploads/sucuri/”, it doesn’t writes into the database at all, unless you have a very-very-very old version of the code from more than 3 years ago.
Can you ask your hosting provider for a copy of the crash report when your site went down? I would appreciate a copy of this report so I can investigate what actually happened with the plugin during the WordPress update. You can send the report to [email protected] I will wait for it. Thank you in advance.
[1] https://github.com/Sucuri/sucuri-wordpress-plugin
[2] https://github.com/Sucuri/sucuri-wordpress-plugin/pull/29
[3] https://github.com/Sucuri/sucuri-wordpress-plugin/archive/master.zip