I have added the ability to delete users in batch and will release it as part of v5.2 of the base Bulk Delete plugin in about a week. Unfortunately the change had to be made in the plugin and not in the addon as I previously thought.
If you can wait for a week till I make the release, then you can automatically update from your WordPress admin site. If you need this feature right away, then you pick up the changes from this commit https://github.com/sudar/bulk-delete/commit/2588fd889e60e8e9a369f62b7e38524359099bec