Nothing “we” can do. If he submitted it to Epic, then just waiting is the only thing. I don’t think Epic will just blindly release something. Even if its an update to an existing item. They still need to test that its not malicious, broken etc… before releasing it.
If the plugin is ready as he says, he’s done his part (thanks).
However, people can manually add the plugin if he releases a download of it somewhere I’d think like other plugins released for free or bought of Gumroad etc… so not sure if thats a possibility.
Otherwise, make a copy of your whole project folder and label it as 416. After convert the original to 417 and launch it. See the errors for the missing parts when it starts up that use the plugin. If its not too many places… you can redo those manually without using the plugin nodes.