Opp. Plans Settings
The Opp. Plans tab allows Admins to control standalone behavior on Opportunities, enable ClosePlan deployment by Members, and link an Opportunity Plan from another Opportunity.
Standalone View Options
Allows Admins to enable Deal Teams, Deal Chatter and Files in the Standalone ClosePlan Application.
Result:
Miscellaneous
Allow ClosePlan deployment by Members
ClosePlan can be deployed only by Opportunity Owners and Users above in the hierarchy by default. If this option is enabled, any user with edit access will be able to deploy ClosePlan.
Link Opportunity Plan from the Other Opportunity
Enable users to select and link a plan from the parent Opportunity, if one exists, instead of creating a new one.
To activate this feature, enter the API name (case sensitive) of the Opportunity Lookup, Text or Formula (text type) field that represents the parent-child relationship between opportunities.
Up to four fields can be entered separated by a comma, with the order determining the priority.
Result when the user goes to create a ClosePlan on the Opportunity:
Linked ClosePlan can be Unlink from the Opportunity Widget.
Depending on the org settings, users may or may not be able to edit it, or even view it, if the Opportunity has private sharing settings.