Just a blurb reply..

UVMaps are all about texture space - How much do you have to work with, memory wise? That's a consideration because, depending on the resolution you're rendering the object at, you need more detailed texture maps/image maps for it to render well.

When an object loads, the UV map tells the renderer how to assign textures to the surface of the object. Depending on the renderer and the materials used, the maps may not have to be very good or even exist.

I haven't seen the original object, but it appears that someone assigned marterial zones/groups to each individually crafted bit of geometry. Then, they hit a "Derpy Map This Automagically Button" and walla... that's what you get - Each material has a UV Map suitable for using seperate texture maps.

This is perfectly fine if you're using only materials, like in Poser's Material Room. It's also perfectly fine if you're using several separate texture maps, like Victoria 4 uses, and all of them are at the appropriate resolution to yield a good render of the object. But, if you're trying to maximize memory and minimize the number of files necessary, it's not good for that at all. You can't just use one texture map (jpeg or whatever) for the whole object. So, if you want to do that, you have to remap the object so that just one image is suitable for the texture map.

When doing that, then you must follow the cardinal rule of mapping - Those things which need the greatest texture detail from a texture map (jpeg or whatever image map is being used) get the most space allowed on the UV Map.

That's where the "Art" of mapping comes into play with the knowledge of the object's intended use. Crafting a good map depends not only on good UV Mapping skills, in general, but on knowing how the user is going to use the object. It's also helpful to know at what resolution the object is likely to be rendered.

For instance, on that object, I'd bump up the label material on the UV Map as much as I could, leaving very little space for the buttons. Why? The texture of the letters is going to need the most space in order to be legible at the greatest range of resolutions and buttons can just use procedural shaders and still render in high quality at just about any resolution.

The case would get the next space allotment. It may need a custom bump or even some signs of wear and tear that can't be realistically generated by procedurals.

So, in order of importance for intended use and the necessary space requirements as well as likely intended material assignments,  you'd have:

1. Label(s) - Texture map (A jpeg/image map) + Procedural materials

2. Case - Maybe a texture map + Procedurals

3. Thumb Control - Procedurals, mostly, maybe a displacement map would be necessary if the little details aren't modeled in. (Don't have the model to check.)

4. Big Buttons - Procedurals, entirely. Use procedurals for wear and tear, as well.)

5. Little Buttons - Procedurals

6. Other - Procedurals

Procedural materials don't care too much about UV Map allotted space in something like Poser. In most cases, with normal procedurals, the map can look like a rat's nest and render well. For most purposes, it's only image maps/texture maps that need adequate space allotted in a UV Map in order to render at the intended resolution. Since this object appears to make critical use of image/texture maps for its label, it's critical that those get the most space on a single map.