What is the proposed idea/solution?

Today the only way to add buffers between dependent project tasks (i.e. tasks where one task is a predecessor to the other) is to view the project in timeline view. You have to click on the dependency and manually set the buffer. Many of my projects depending on adding a delay to the start of a dependent task after its predecessor is completed and having to hand add buffers in timeline view to support this is not sustainable. 

How does this solve the user problems?

This allows to a scalable approach to project creations via record templates where users need to add a delay between the completion of one task and the start of the next task dependent task (i.e. this task has a predecessor defined) without doing a ton of manual work in timeline views.