Exclude textures from "Texture Quality" setting

Hi guys!
I have a question about "Texture Quality" option (in Quality Settings), that globally changes textures resolutions.

(Second row under "Rendering" - it's set to Full res")

I use it in my game's options menu, so player is able to change textures quality, and improve performance. But changing it also affects lightmaps (baked in Unity 5) - and it makes them look really bad (pixelated shadows, seams everywhere). They look great in "Full res".
So, I'm wondering - is there a way to exclude lightmaps (or other textures) from this quality setting, in any way?

Thank you for your help!

 

I'd also like to know if there's a way to do this. I know disabling mipmaps stops textures being downsampled, but there are some GUI-like textures we have that are used in the world that need to stay at the resolution they're set to.

There must be some way to exclude certain textures from being affected by general texture quality downsampling?