Geometry sort / regionating , class cast exception when attribute is not a geometry

If you select regionating strategy: geometry

But then select a regionating attribute that is not a geometry, the form will let you do so, and the code fails with a class cast exception in
getSortAttributeValue(SimpleFeature f) , line 74, in GeometryRegionatinStrategy.

Can we have the UI fail if the attribute is not a geometry, the same way it fails if you do not have a bounding box set ?

Feel free to assign back to me if you have more important stuff.