How to make room in ASZ (Acronis Secure Zone)?

Currently I've got "When not enough space in ASZ, delete the oldest backup" enabled, so I've already done that step.  

I also went through and adjusted my backup settings to only retain seven days worth of backups, this should have cleared as much as 70% of the used space in ASZ by deleting old, unnecessary backups.  

So I've followed the top two pieces of advice I can find and neither of them has created any more space, Acronis seems unwilling or unable to delete the old backups in ASZ, and the only way I can find to manually delete the old backups is to delete the whole thing and start from scratch, which I'd rather not do.  

Is there a "Clean up versions..." option for ASZ the way there is for normal hard drive based backups?  If so, how do I access it?  

As I said, I'd rather not nuke the whole backup scheme and start from scratch, if I can avoid it.  I'm sure Acronis wouldn't have created ASZ without a way to clean up files once the drive gets full, that would be an absurdly simplistic oversight on their part.  Anyway, what should I do here?