I don’t know if there is any alternative but this is one of the best plugin I have ever used even on all cases.
It corrects if there is any same Tag or Slug saved and it excludes them from the list without an any error. It’s so easy to use. I even add 20.000 tags once a time and it did in seconds.
I totally suggest to ue this plugin, gladly.
Thank you so much for the developer.