If ever you're using mipmaps, it will look like shit. lots of extra vertices + no control over texture space + no padding + no way to edit it in photoshop = very bad idea. Also i'm not very familiar with zbrush but i'm pretty sure you can unwrap your level 1 mesh in an external package then re-import it without affecting…
Several team members on project I'm in insist on using zbrushes auto uv methods to not bother with unwrapping their low poly meshes properly to save time. I am trying to convince them that it is not good performance wise for the game assets to be unwrapped liked this. That they should unwrap the low and transfer the zbrush…