UV Unwrap Modifier?

Hello. I have a workflow related question and I hope this is the right category. I was wondering if there is a tool or a way in blender unwrap while in mirror modifier. The idea is that i don’t want to lose the mirror modifier, but still want to unwrap the mirrored objects. I know that unwrapping the original translates to the mirrored ones, but the problem is if I want to make lightmaps. Texture atlas tool, which I use, disables the modifiers and unwraps only the original objects, which sucks. When I’m done with the texture atlas tool, of course the mirrored objects will have overlapping UV’s. All this is no problem if I simply “collapse” the modifiers, but game development workflows needs to be as flexible as possible, that’s just the way it is and losing steps to go back or redoing things is not very convenient. Does anyone know if there is some sort of UV Unwrap Modifier? (Not UV warp) or some other way to solve this destructibility issue, so i can make my work flow more indestructible?

To clarify a bit, I have an exporter that applies all the modifiers, resets scales, renames etc “internally” all in one buttom, so my scene stays the same and I haven’t lost anything

Thanks.

In future updates provide us with your .blend file to resolve your issues more easily. While in UV image editor you can press ctrl+A and ctrl+P to resize and restack your UV’s to avoid overlapping. I don’t see any problem with UV unwrapping and mirror modifiers being kept. Don’t forget to check U and V coordinates in mirror modifier before applying it to the model.