Here are two enhancements requests for batch renaming. Both of them should require just a few lines of code and would enhance our daily workflows greatly.

Let us use longer image names.
The text fields offer plenty of space, yet you only offer us space for names up to roughly 25 letters. For our use-case we always need far longer names. They never fit the current field. It was an easy change to make the current field grow, when longer input gets detected.

Give us a checkbox to reset the "sequence number" field. This would make work with series of images a lot less tedious. I even suggest making "reset" the default value (checkbox checked) – I cannot imagine a use-case where contiguous numbering between renaming sessions was desirable.

The attached paint over shows the proposed changes.