That behavior change was reverted in 7.3.x
You could go back to 7.2.3, it still has most of the speed optimizations.
Some people complained that it wasn't using the Series/Vol field so it got reverted. Some comicvine metadata has the title field be stuff like "Volume 1" which is a bad default.
Can you just use the filename instead and not set the fields in comictagger?
What does a comictagger xml file even look like if its generated from comicvine? did you get data from comicvine?
This was relevant discussion:
https://github.com/ciromattia/kcc/issues/854