Does Unchained Capital recommend using a BIP38 passphrase on top of my wallet?

No, we do not.

Generally, it's not recommended 

A BIP38 passphrase, otherwise known as a 13th or 25th word, is commonly used with singlesig wallets as an easy way to add an additional layer of security, with the key caveat that if you forget or lose your passphrase, you no longer hold the key to your bitcoin. 

While we understand the desire for extra security with securing your bitcoin, adding complexity can actually be a security threat itself. We have found that in many cases, clients lose access to their funds not because of a lack of security, but because of having too much!

For this reason, we generally do not recommend using a BIP38 passphrase in combination with multisig, since multisig already adds ample security and eliminates single points of failure.