Part of my method does include naming the areas. The top grill is little boxes - each has a top, side, front, back. Now if they are all going to be the same color, but different than the rest of the mesh, then just select them all, make them a Vertex Group (“Top Grill”) and it doesn’t matter how you unwrap them - they can even be on top of one another on your map - they will take the material of the map, they don’t see each other. In other words, if all those little boxes are to be the same material on all surfaces, you don’t need to map them out in any organized and separated way.
But let’s say you wanted all the tops one color, all the fronts another, etc. Then you would select all the fronts and make a group of them and unwrap them, using perhaps Smart UV Project, since you can’t get a flat-on view separating all the fronts. Then you would select all the tops, group them and unwrap them using an ortho top Project from view, etc.
Individually selecting, grouping, and naming all those faces will take 5 minutes or so, but if that’s your design plan (different materials for top, front, back, etc of each little box), then that’s what you have to do.