Cushion or curved surface

Making a cushion for a single panel (Option-1) seems ok. But when I repeat it for the whole pattern, it takes too long. I could not guess the problem even though when I reduced the pattern for a few rows. I am not sure if using this way to create an air cushion is suitable!

I was thinking of changing the way of making the cushion to be a normal surface created from the base of the panel and different curves (Option -2). The problem is that the curvature of the surface is incomplete and not smooth. Also, it takes a very long time to repeat this over the entire pattern. In fact, I am not sure if my way to create the points of the arches are correct or not!

Please, can anyone help me with these issues: solving the problem of the running time and creating curved surfaces? (27.9 KB)

Hi, is there anyone who can help me with this issue, please?