When an app has been notarized, yet there are errors in the plugins like the example below:

Example Plugin Notarize Error:
"severity": "error",
"code": null,
"path": "myApp.zip/myApp.app/Contents/Plugins/CS64.bundle/Contents/MacOS/CS",
"message": "The signature of the binary is invalid.",
"docUrl": null,
"architecture": "x86_64"

Thie error means that the plugin must be signed and notarized outside of the app and prior to notarizing the app. The steps should be as follows:

1. Sign and notarize plugin by itself

2. After plugin has been notarized, move notarized plugin into the app's plugins folder (E.G. someApp.app/Contents/Plugins)

3. Notarize the built app

From here, the built app should no longer receive any notarization errors regarding the plugins.