I think the move to GP was out of necessity. Birse did it as a loss leader to try and capture the out of town purpose built stadia which came about around the time of Hillsboro.
I haven’t met one iron fan who wouldn’t swap it for OSG. It was a fantastic place to watch football. Every one of my mates who doesn’t support Scunny has a story about the OSG. I reckon 80-90% of the town went at some point in their lives to OSG