You have large circles that are embroidered and in between those it looks like diamonds or squares on point. Some way of joining the two could work: since your embroidery designs line up along the diagonal, maybe you could first join them with diagonal lines. in two directions (creating a large scale grid on point) and then use the grid to help you divide the space in a way that would add texture and allow the embroidered areas to pop above the surface a little. But I wouldn’t do too much in the way of variety of quilting patterns since you want the embroidery to be the focal point
Alternatively, you could echo around all the embroidered areas. Since they are not quilted, echoing around them would flatten the background and let the embroidered areas stand up a bit. And by echoing the embroidered shapes you would be focussing the eye on the intricacy of the embroidery by creating radiating texture around each. Like ripples in water.
Rob