Hello @Stan,
The only way to truly achieve this (with mediocre UX however) requires an Enterprise subscription. It goes something like this:
- Create a custom property that is required for moving a deal forward
- Set the property to view only (this is the Enterprise part)
- Only update it via workflow when the fields of the associated records are filled
Unfortunately, that would not expose the actual fields on the associated contacts when moving the deal forward - it would simply block the deal stage movement. (And an accompanying documentation would have to point out that fields on the associated contact would have to be updated.)
Using the middle section of the deal record, it would be easy to show the required fields of the associated contacts. They simply wouldn’t be enforced.
Besides that, I’m not aware of a way to truly block deal progression based on associated records.
There is a request to the product team on this feature here: Make properties on associated records required when moving a deal to a deal stage
The product team reviews these requests based on popularity - so I’d recommend upvoting and commenting.
Best regards