Yes, I play a freebase Pigini, a freebase Giullietti, an Ellegaard with converter, a mini-hybrid bandoneon (with 3 rows chromatics for each hand) and I am awaiting my Adolf Arnold bandonion with Adolf Arnold Peguri layout.
Pure piano notes may be unsuitable but can be a good start. Remember all the time that you don't do runs on buttons the way you do on tangents, but you can do much more with chord play on buttons. Books on accompanying for piano that cover playing melody and accompaniment together will show you a lot. Ellegaard wrote a tutor for Hohner on free base. You can find it on amazon and it gives worthwhile exercises. Keep training your left hand. Bandonion and free base playing is two-handed whereas Stradellan makes a lazy left and dominant right.
Play canons and simple duets with your two hands. You are in for a beautiful time.