Come up with a design where OneDrive For Business can be set for External Sharing at each Individual User OneDrive level
Currently when you set OneDrive for External Sharing - its a tenant setting, meaning all users in a tenant with OneDrive can share externally. This is a nightmare for governance perspective for any mid to large corporation. OneDrive External Sharing needs to be configured in a way where a user's OneDrive can be configured for External Sharing and others are not.
Also to configure OneDrive for External Sharing, SharePoint Sites should not be a dependency to be configured for External Sharing. Now SharePoint sites can be created through many services and this is absolutely a big headache to manage.