I have same problem using v 1.2 on wordpress 5.3.2 . All Mysql disk used and there are thousands of longer-permalinks-post-name-longer values in the Table.
Sorry for answering late. I can not reproduce the error too ?? but If it helps my last wp version was 5.0.3 and I am using the multi-site feature.
I’ve upgraded to the 1.16 version of your plugin and nothing broke yet.
I am using that version. My problem is not updating from wp 4.x to 5.x. It is updating from 5 to 5.1.
After that, the Database will break. I think you should update your plugin once again to avoid this problem after each major or minor update.