the way you do information density btw is say "include all unique insights, facts, figures, data points, predictions, timelines, and otherwise important information with 100% fidelity"
Yep, then from that I would have an options panel to toggle only the things you want to see.
The other thing I would do on AIbriefs is have spacebar shift the card-list viewport right to the top and hide the top-most card.
This way reading the site entails loading the page and hitting spacebar after each card is read. This can already be done with Hackerbrain user-script while reading top-comments for any HN item - spacebar or clicking an item's green badge.
About full articles - this could be a toggle switch. Perhaps have an options panel somewhere. Allow for hiding of much of the content. Have a 'bare-bones' preset.