CAdES is an acronym of "CMS Advanced Electronic Signatures" and it's defined by RFC 5126, which states that CAdES "can be considered as an extension to RFC 3852 (CMS - Cryptographic Message Syntax) and RFC 2634 (Enhanced Security Services for S/MIME), where, when appropriate, additional signed and unsigned attributes have been defined."
Unfortunately, out CMS objects (SignedData, EnvelopedData, ...) only support CMS (RFC 3852 and RFC 5652) - there is no support for extensions defined by RFC 5126 (CAdES). Even though it might be possible to implement a full CAdES implementation based on SignedData object, it would not be trivial and require a fair amount of knowledge of RFC 5126 (CAdES).
We will definitely look into the possibility of adding CAdES support ourselves, but this would take some time as well because we are not familiar with CAdES either. Once we look into this, we will let you know. However, this won't happen in a month or two. Sorry!