As per the August 2021 release blog (https://community.anaplan.com/t5/Releases/August-2021-Releases-and-September-Sneak-Peek/ba-p/118347) there is now an option to "Open the source module" directly from a card.
However, this option only appears if the user has Page Builder access - is this intentional, or can it be configured to show for non-Page Builders?