Thanks for the speedy response, David. Some follow-up questions.

FYI I am using the new file formats - not legacy.

1) Will the retention policy change date be related to the actual files or the full/inc backup date?

e.g. scenario

Retention policy is set to keep files for 4 months.

Backup is set to run daily at 3am.

For the month of July, there are full + inc backups from 07/01/21 - 07/31/21, and I can see the full gen set in the backup storage tab.

In August run, to delete all the files from July, I would then set the retention policy to, say, 30 days. But that would then delete all the files backed up in July, instead of specific ones I no longer need.

2) Isn't there a way to have a backup delete from remote storage files that were already deleted locally? Sort of a sync?