A patch is embroidery with nowhere to hide. There is no garment to sink into and no seam to break up the eye: every stitch sits on twill, fully visible, right to the boundary.
The border has to match the finishing method. A merrowed edge needs an allowance for the overlock to bite into. A laser-cut edge needs a dense satin wall at the cut line or the twill frays the moment it is handled.
Get the edge wrong and it shows straight away: fraying, base fabric peeking through, or a merrow that eats into the design because nobody left room for it. If the patch is going onto a garment as a direct stitch instead, that is a different build; see logo digitizing.
Tell us the edge finish before we start. The same artwork is digitized differently for merrowed, laser-cut and heat-seal patches; it is not a decision you can make after the file is built.