Setting aside the issue of Diners USA participating, Priority Pass now seems to say that the associated credit card can be used for lounge access. If this also works at restaurants, it
might allow Diners Club holders to use those locations without a Priority Pass card.
Can I access a lounge without my membership card?
You will need to present your physical, Digital Membership Card or eligible payment card when entering a lounge.
https://memberhelp.prioritypass.com/...mbership-card-