I’m a long time EagleFiler user. I mainly use it these days as an archive for thousands of old files that I want to keep. But, on occasion, I will create a library just to de-duplicate PDFs and photos, etc.
It accepts all kinds of files and separates duplicates on import. Once import is complete I remove the folder containing my sorted files and discard the rest of the library (which includes the folder of duplicates it rejected).
As a test, on a couple of occasions I used Gemini II then EF on the same batch of files. EF caught duplicates G2 had missed. Since then I have only used EF.