This is essentially how I was attempting the form before studying with Marin. Very big, circular, and softer. I was also stepping with weight centralized. I believed that was correct because you see that in all of Chen Fake's students. I did most of the moves like that. It was easy on the knees too.
The stance tends to widen more when you don't maintain the empty step. I think you see that with this man. In the forms I have seen by more advanced Gongfujia practitioners, they also appear to centralize the weight (or maybe it's 60/40) more or less. I thought keeping the weight more centered would generally be better for fighting.
Probably, when you get old, you just relax and do your form the best you can.