Normally, there can be multiple deal types under the same lead. But in the case that a customer wants two projects done on the same property (shed and home, etc.) but wants the system design, data, and or financing to be separate from each other, then it is useful to create two separate leads instead of two deals since only one deal per lead can be fully completed.
Within V2 the user can make multiple designs and look at various proposals for the same deal type and same lead BUT the user CAN NOT move forward with multiple designs/proposals within the same lead. In this case, the user would also have to create a new lead to move forward. In order to do this, one lead can be labeled as "Unit A" and the other "Unit B".