Using Customer Testimonials Beyond Traditional Case Studies

I love this recent LinkedIn post from Mark Huber about focusing on screenshots of LinkedIn posts, Slack messages, or email replies as actual proof from customers, rather than grand polished traditional case studies. I'm ideating around collecting more of these small nuggets in our company (there are plenty), but many come from our implementation phase, which is a several month period where the customer works with our implementation team to fully setup and integrate the software. How do others use positive testimonials from these periods of a journey? Do you anonymize it and use it for marketing, etc? Do you ask the customer to get it approved so it has a name/face with it when using it for marketing, etc?