IMO and IME, shea butter is an excellent sub for palm oil. Avocado oil is high in unsaponifiables and should be used at no more than 15% of your liquid oils in your formula. It's especially nice for making avocado face soap.I personally am going to experiment with a straight sub between palm oil and avocado oil, probably going a little higher on some hardening oil to compensate. And adding something to harden.
BASIC TRINITY OF OILS