Currently, the data integration between MMC and MCC is unidirectional. This means that, whenever any linked field is changed in MCC, every linked field in MMC is overwritten (including subscription status). This has the potential to subscribe customers to an email list from which they have previously unsubscribed (which is illegal), and vice versa (which is also not ideal).
E.g. (1) A customer shops in-store and subscribes to the newsletter, which adds them to MCC as subscribed. This data flows through to MMC. (2) The customer then unsubscribes through a marketing email, which marks them as unsubscribed in MMC. This data does not flow through to MCC. (3) The customer changes their address in-store via MCC. This data flows through to MMC, overwriting every linked field, marking the customer as subscribed in MMC, with incorrect and outdated data.
The current 'work-around' is to maintain two lists in MMC, and have staff manually subscribe customers via the embedded or pop-up form on the website. Essentially making the 'Newsletter Subscriber' field, which comes up in POS and during web checkout, non-functioning.
Any changes that a customer makes in MMC (subscription status, custom linked fields) should flow back to MCC via bidirectional data integration.
