Once an interpreter is created, there's no way of checking which interpreter plugin it's using.
Install the module and go to admin/config/regional/recurring-date-interpreters/manage/default_interpreter
The form should show the plugin -- either as a form element (if it should be possible to change it) or as a locked element (if it should not be changed).
[[Remove this:] Replace ❌ with ✔ where applicable]
Active
3.4
User interface
