I am looking at my custom preference center and email opt outs and attempting to determine some best practices.   

We have an ecommerce lead record type in SF (and use the MC connector).  We have 4 brand.com sites and so we have 4 fields on lead for opt in (one for each brand).

Ideally, we want keep track of (and keep in sync) who is subscribed or unsubscribed for each brand.

Each brand is a different BU in marketing cloud.

On our custom preference center, we want to use the custom opt in fields on the lead and want to avoid using the hasoptedoutofemail field.  And, we want to keep SF and MC in sync.

This set up has caused us a considerable amount of problems.  Is this a good, common, or best practice type of set up?  or, is there a better way to achieve our goals?

Here are some challenges we are facing:

- recently we revamped our custom preference centers to attempt to properly manage the hasoptedoutofemail field and our custom fields.  Yet, there must be some problem in that code.  SF seems inconsistent when comparing hasoptedoutofemail to custom opt in fields.  The code is quite complex to attempt to unsub in MC, use custom fields in SF, and reset hasoptedoutofemail in SF after each update.

- I just discovered list unsubscribe via RMM (i.e. yahoo, outlook, gmail, etc) and that sets the hasoptedoutofemail field via the MC connector and knows nothing about our custom opt in fields

- I just discovered Spam Complaint (i.e. yahoo, outlook, gmail, etc) and that also sets the hasoptedoutofemail field via the MC connector and knows nothing about our custom opt in field

The bottom line is that I'd like to take advantage of MC built in capabilities like List Unsubscribe, Spam Complaint, and the automated update of hasoptedoutofemail via the connector.   However, I am hampered by the need to have unique opt in/out by brand (our brands are diverse so it often makes sense that someone is opted in to one brand but out of another.

Is there a better way to manage opt ins and opt outs that is not so complicated as the process we have today?

Or, is this just a common issue that many companies have to deal with it and I just have to deal with it also (i.e. tighten up my custom preference center, build automation opt in/out sync processes to address list unsubscribe by brand, etc)?