New release of Drupal Code Builder. Version 4.5.4 adds adoption of plugin types from existing code.
This allows easy conversion of annotation-based plugin types to attribute-based plugin types!
1. Adopt your module and its plugin type.
2. In the plugin types section form, change the discovery type to 'attribute'. This will preserve data such as the plugin subdirectory, and annotation properties.
3. Generate!
You can then use #Drupal #Rector to convert plugins of this type to use attributes.