For information, for those following Apple/iOS/Safari news, Apple’s recent announcements regarding web storage management (cookie/localstorage/indexedDB) do not pose a problem for the PWA that is Gladys 4 / Gladys Plus!
As indicated in their post, cookies deleted after 7 days do not apply to web apps added to the home screen:
Source: Full Third-Party Cookie Blocking and More | WebKit
Good news for Gladys!