GTM Template – Tag – Local Storage Interact (EN)
https://antoine-hervillard.com/gtm-template-tag-local-storage-interact/
Custom template permissions
https://developers.google.com/tag-platform/tag-manager/templates/permissions#set_cookies
Cross-Domain LocalStorage
https://jcubic.wordpress.com/2014/06/20/cross-domain-localstorage/
gtm localstorage data cross domain transfer