One point I will continue to make is that I do not see how DL will allow hundreds of daily CO PC members to be refreshed at DL's expense if there is no side arrangement between the two carriers. Simple lounge reciprocity doesn't really cut it when you are talking about one of the largest CO stations (non-hub) in the country.
I was under the impression that generally, they contractually keep track of the visits to each others' lounges and if there is an imbalance, there is a fee per passenger.
The ORD lounge has a CO podium, while its considered a "joint" club, its really a worldclub (WC bar/snacks/furnishings), both airlines share the operating expenses. They could do something similar here.