We've added a great new option to Bitrix24 CRM. Now you can add observers to a lead or a deal, and observers will be able to view the CRM element, send and read messages in the chat of the element.
Discuss important information about every lead and deal in the chat and get back to it at any time later, as the chat remains even after CRM entity has been converted.
Give it a try! You're absolutely gonna love it!