[kiwidude]

@stanmarsh - give this version a whirl. By default the batch size is 100, but you can increase/reduce it in Preferences -> Plugins -> Extract ISBN -> Configure plugin.

Note that there are a couple of side effects if the number of books you have selected is more than your batch size causing multiple jobs to be run:

1. You will get prompted each and every time a batch completes. This will not be changed and is the same behaviour as what you see with bulk metadata downloads.
2. As part of the output this plugin displays what books it did not even attempt to retrieve data for (e.g. book had no formats). This information will now get displayed on the first batch job completing only.
3. There is an option which some users have turned on to execute a search to show which books have been updated. If you use this option, you are only going to see books for that batch. When the next batch completes, you will then only see books for that batch and so on.