With traditional Cajun music it's allowed to play out of tune with the bass-side of the accordion.
I allways play the bass-side.
Some bands with drums and bass-guitar or bass-fiddle don't use the bass-side on the accordion.
I have seen Steve Riley twice and he's using the bass side both times.
There are ten-button accordions with more bass opportunities and there's something about that on this forum. For instance : you have a G-bass or another on the pull and on the push too.