Forwards and Backwards Compatibility with Custom Functions

We have previously built a MathCAD wrapper for the CoolProp (www.coolprop.org) library of fluid properties.

I am rebuilding the wrapper for the new version of our library, and I was wondering what versions a custom function built for Prime 3.0 would be compatible with. Would it be compatible with MathCAD 15.0? Has the ABI changed since 15.0?