Being an algorithmic penalization, I guess is mandatory to change the content on the cloned site. If not, when Google recrawls it, will penalize the new site too.I love my domain tooI have 1 more authority site (Not the one in the case study) that was affected and I don't want to rush it yet. But if you want an honest feedback. Wait for a week or 2. I just redirects one of my lovely semi-authority niche site that has been making $1k for months.
What I did before redirecting, edit old posts and add more content, remove all link back to the homepage. It is a static page, so I reduce the mention of the primary keyword. Use a lot of variations of the KWs. (i.e. blue widget, widgets of blue etc.).
What I will do in the next week. Add more content on some old posts and new informational articles.
Send some social signals to the homepage and other landing page.
Buy an SEO service and use more than 10+ anchor test for it.
Add more content.
Then wait for another 1 week to see how it will go. (You can get in touch then, and I will tell you if this works or not.)
Thanks.
If redirecting+modifying the site+ sendin new links recovers it better than just modifying the original site + adding new links is what's difficult to say, I guess.
Will keep reading about your experiment!