Here is a trick to speed things up. If two documents are the same, then their size will be identical. If we cannot rely on the name being identical (because we renamed a few), then we can search by type (filename extension) — that's bound to be the same. So instead of ticking the slow Content option, tick the Size and Item type property as seen in the picture to the right.
The results aren't 100% guaranteed to be duplicate files but xplorer² will find them very quickly. You can manually preview the documents and confirm whether they are identical or not. Or you can have a second pass on these rough results using the slow (but robust) scan by Content option.
ps. Happy easter, if catholically applicable!