So, I am a firm believer in ungated case studies.
THAT SAID, something I've done before is have case studies ungated on the website and then included a button to download a PDF. That PDF is behind a form. So lead capture + impacts our lead scoring/shows maybe higher intent.
We're working now on how customer evidence can be used in the sales process -- recently brought in an awesome VP of Solutions Engineering who is helping us with that, since our team was not used to leveraging customer evidence (other than references) in the sales process.