Was able to test on OS X, and first had some errors relating to db in calibre, but formatted internal memory for a clean slate and working great now.
Tested syncing books/collections based on series and works as expected, very nice work. There is one minor bug wanted to point out. It looks like the plugin configuration screen is not displaying all the text, but other Sony driver shows it all. Attaching screenshots of both:
PRS-T1 config (missing collections config text)
Sony config (shows full collections config text)