The Italian virtuoso, Wolmer Beltrami, was one of several in his day who also never used shoulder straps.
Some players use the right strap only, some use both but place the right strap across their upper arm, and not their shoulder.
Some older Belgian players use a detachable harness that clips onto the accordion.
Accordion stands which permit playing standing up with no straps are popular in Italy.
When you are my build, Big accordion=two straps, Wee accordion=right strap only. I find that with experience I no longer need shoulder straps when I'm playing the harmonica, but everybody seems to have their own preference.
Best option is to get all the books that tell us there is only way with all things accordion and throw them in the fire. Only problem is I'm waiting for somebody to write a book that tells you the correct way to light a fire!
Red traffic lights mean stop (but not everywhere). In Greece they mean stop "only if it is safe to do so" . If the driver of the 38 tonne lorry behind you is arguing with his girlfriend on his phone and accelerating towards the lights at 100kph, better risking a 750 Euro fine as trying to claim thousands back in hospital fees.