MyCloud App Search Capability

No (although your local PC may still ask for the confirmation), but what you can do is enable the recycle bin on the Mirror. Then if you delete something on it, rather than just erasing it, the file/folder is moved to the recycle bin (a bit like Windows does) and you can recover it from there if required.

Is set on a per-drive basis (if you’re using JBOD or equivalent), and of course you don’t gain any disc space back until you actually delete the file from the recycle bin folder.