No, and this one is not a judgement call.
Holding full card numbers puts you into the highest level of PCI obligation, which means an annual on-site assessment and a quarterly scan, and it means a breach at your end is a card breach rather than a bad afternoon. Almost nobody who asks for this wants what it actually costs.
The real need underneath it is portability, and that is fair. Larkspur supports a network token migration: your provider and ours exchange tokens directly, your customers enter nothing, and no card number ever sits in your database. Ask us and we will start one.