Here is a clip of Gaston Nolet (video from YouTube.), one of the masters of 3-row diatonic accordion playing in Quebec. Watch carefully for his use of the "inconvenient" accidentals at the end of the keyboard closest to the chin.
I have heard Gaston Nolet in a variety of contexts over the years and have always appreciated the variety of tunes that he presents. Gaston manages to preserve the jewel-like quality of each piece, yet commands a repertoire of staggering proportions.