I think the comments as above stand. The underlying data encryption is very secure.
The filename encryption is pretty secure, but has a weakness “filenames with the same name will encrypt the same” because it uses what is effectively a very wide ECB cipher block mode and doesn’t use a nonce because we require file names to have a unique mapping from plain to cipher text. Because the cipher is a wide cipher over the whole path element it doesn’t have the normal weakness of ECB mode unless you have identical path elements.
We haven’t made any progress on a more secure file name encryption mode.