The plugin is Edit History by Scott Vivian. Even though the edits are being recorded at MySQL, nothing ever shows at domain.com/revisions. Everything I get is the message "This page will list posts that have been edited recently.".
That part has not been developed. I've been pretty busy with some personal issues recently (and before that, work on my own site) so haven't had time to work on my plugins.
However, you may want to check out this issue on Github: https://github.com/svivian/q2a-edit-history/issues/12 - echteinfachtv (a regular visitor here) posted some code that should do that for you. At some point I will integrate that into the plugin myself.
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