I find that behind the dash can get pretty warm when the heat is on, which is understandable considering there are numerous ducts in there. Enough that I put in a fan to keep the raspberry pi cooler. Never hit thermal throttling, but it was getting up there. Never noticed the front face getting warm though.
The stock head-unit (assuming they are all somewhat like the soundmark) has a tiny fan to cool the MOSFETS.
But, as you indicated, the lights are intermittently working, I’m going to go out on a limb and say there are other issues. I would definitely try and figure that out sooner than later, because if something i getting real hot.. that could end badly