I'm wondering what tilts you in the direction of my proposal.

Off the cuff:

• Not having to worry about strict or use vars or our and backwards compatibility. Your approach just explicitly forces fully qualified names.

• External fully-qualified names makes it clear where the mappings are used. I think that will help those maintaining the code follow the action.

• Doesn't pollute the package namespace with a special variable the package doesn't even use itself.

(Regarding globals and local: Yes, indeed. Have you seen Object::LocalVars?)