SAP Sales Cloud v2 - Retain contact communication details like mobile number upon change of Account

[anypre]

Hi Experts,

Here, anyone would have any work-arounds to retain the Contact communication details like mobile number/ email address upon change of Account? 

Back-ground: currently in SAP Sales Cloud 2, a Contact can be linked to multiple Accounts, but only 1 of the linked Accounts can be set as Main Account. When user removes the Main Account tag, suddently without any warning, all the communication details like email address, mobile number, phone number of the Contact would also be cleared to blank without choices.  This system behaviour is not aligning to our business requirements.  Depends on the actual situation, our users would like to retain these information by default and to clear or update them manually.  For example: Sometimes, users may just want to correct a generic data entry issue to reset the Main Account.  Often some of the Contact's communication details have nothing to do with any Account(s), like mobile number. 

We had explored to use custom fields, but not acceptable. There are too many system behaviours like click to dial, calling buttons/icon, system column adaptation is not yet able to applied to 100% of all areas, etc

Anyone would have any other work-arounds?

Regards,

SW