@kanga The closest thing Blender has is "Minimize Stretch" which may work for this but it's not as advanced as the UV relax tools in other 3D packages.
I'm currently having an issue where my mesh is showing black spots after applying my normal map. I checked that the Ray's are pointing in the right direction and made sure that my mesh could handle the amount of details but I'm still running into the same issues. This is a project that I am working on in blender
You have overlapping polygons. I dont believe there is a real relax in Blender's uv editor, which means I havent found it yet. A quick fix is to manually move the verts in the editor so there is no overlapping. Just spread out the trouble spots and give them a bit more room.