In the SPPB 5.3.3+ JoomShaper added the possibility to use Custom SVG Shapes for images used in the Image addon. As the first step, you have to generate an SVG shape and then use it as a base for the image. Use the Scale Image option to increase image size. I used an online generator from: softr.io/tools/svgshapegenerator but there are several more on the net. Remember to use clean SVG Code!