Validations to force user to add line item and avoid any impact on integration

Is there any way that we can force user to add line item whenever user updates the BP record (Non-workflow type)?

Also, we don't want any impact on integration. As for non-workflow type BP, only one form is available. And if we put any validations it is also considered during integration updates.

e.g. We have Monthly Progress BP, which is non workflow and can be updated by User and/or integration, now our requirement is whenever user update the monthly progress BP record, we want him to add the comments in the line item called "comment".