UV Maps and texture slots

Okay, so I am making a hair mesh/frankenmesh - which considering I barely taught myself how to fuss with Blender last night at midnight lol...not too bad! (got frustrated at the lack of hair that would work for me trying to recreate Hanzo from overwatch haha)

I got the mesh how I wanted it (as far as my current skills will allow) and I figured out how to get the ponytail and the bangs mapped onto the original UV...however the little...sideburn things are very distinctive in their shading and try as I might, getting them to fit nicely (with the hair edges AND the grey!!) onto my existing UV map is proving nearly impossible

Is there a way to use two UV maps for one mesh, or is that an impossibility? D:

EDIT: There is an entire section of the original UV map on the hair I'm not using (as I cut that bit off the mesh entirely) so would I be able to load up my UV to PS, cut the sideburn part out I needed, and stuff it onto that unused space so I can keep everything on one UV map? would that show up correctly in game?



on a lightly related note, my first attempt at...anything was the matching beard for this hair/character



well part of it so far...which is where my issue lies - how do I make this so the UV map has both the 3d beard bits (which I gotta do in black w/ grey) while also having flat shading with cheek scruff and whatnot leading up to the jaw? Is this something I'll need to do in photoshop?

When I brought in back in studio, it was a right mess



Discoloration around the edges and the old beard still there??

Sorry for the noob questions! Couldn't find my exact issue elsewhere.
Thanks!!