Capital One has added new features to the app that allow you to view the real time capacity of Capital One lounges and join a waitlist if there is one. Currently it has been rolled out to most cardholders with the remaining cardholders to see this feature in the coming weeks. If you join a waitlist when a spot opens up your sent a text and then have 15 minutes to get to the lounge before your spot is given to somebody else.
Obviously it would be better if these lounges had enough capacity that this wasn’t an issue, but at least Capital One is being proactive about this.