I have iCloud+ the 2tb top tier and would like to expand my iCloud storage to 4tb, however I have 2 x legacy ID's one for iCloud and another for my purchases, the iCloud sign on will not allow further storage to be purchased and any additional storage purchased on the "purchase" Apple ID does not stack with the existing iCloud storage. My question is, has anyone with a similar set up successfully set 4tb storage because I keep drawing a blank?