Refresh only part of the cache?

Is it possible to force refresh parts of the cache?
Lets say I have the whole mount cached with a 7 day age.
But for some reason want to only refresh a subfolder?

Do you need to force an immediate refresh? or would invalidating that part of the cache suffice?

You may want to refer to this, though it is unclear if this works with the VFS or only the directory cache.

After hours of building the cache, I screwed up by upload something directly to the cloud and not thru the cache mount. I did rebuild it from scratch again, but it would have saved quite a bit of time if you could just force refresh parts.