I can tell you that back in the 80's when the Astar first came to Canada the company I was working for had bubble doors and arm rests made for the left side. We did long line work with them for a couple years before TC pointed out that the RFM did not allow left seat single pilot ops.
The Astar was a fabulous long line machine when flown from the left seat, far far superior to using that hole in the floor from the right side. If you have a left seat option available, take it, you will not regret it.