Engagement History Tracking/Audit Capability

Engagements have significant ramifications for what end users see. Given the power and speed as which mistakes can be made it would be good for audit purpose to know who made what changes on an engagement. 

As engagements are not protected by either the creating user or the product (anyone with Engagement permissions can edit any engagement) it is very possible for others to make unwanted edits to an engagement that could then go out and be problematic with no way to identify the cause. 

Ask is for a historical log of who made edits to engagements.