I have a hardened epic leather helm with a virtue pilgrim hat eternal pattern applied and, on a whim, I just attempted to reshape it using a brown highwayman hat eternal pattern and it worked! BTW, yes I got the pilgrim hat pattern back.
eternal ɪˈtəːn(ə)l,iːˈtəːn(ə)l/ adjective adjective: eternal; noun: Eternal lasting or existing forever; without end.
I was surprised to be able to apply another pattern to something that already had a pattern applied, not because I got my eternal pattern back.