For some entities, calling Entity:Activate after this will scale the collision bounds and PhysObj as well; be wary as there's no optimization being done internally and highly complex collision models might crash the server.
This is the same system used in TF2 for the Mann Vs Machine robots.
To resize the entity along any axis, use Entity:EnableMatrix instead.
If your old scales are wrong, use Entity:SetLegacyTransform as a quick fix.
Issue Tracker: 3502