Well, your getting into the motivation for the building of in house game engines. The time factor, if not for art then for code.
You have two different types of post-work. One, to fix, and manipulate, specific parts of the image.
The other to to manipulate the image overall.
I'll be doing both. The only reason at all, I'm doing post work of the second variety (the image overall) is I want a distinctive look to my game.
The imagery from Daz is fine. It has just the look I would expect from a great game anyway. Robust, hard work looking visuals with the main focus on gameplay.
Unlike the original poster (as far as I know), my hobby in my teens was doing 'celebrity fakes' ie. taking the celebrity of the day's head and putting it on a porn picture. That was my learning by doing. My advice to the original poster is if you want to somehow help others later with the skills you have accrued through learning by doing, then find a little project on here to help out on. As you would know, you can lose your ability's later when you stop at something. Now, I was frustrated later when I came back to my photo editing program of choice and found I could not get straight back into it. It's not great when your on your own time in all cases. I was photo editing, it can be complex, Daz is very complex and very hands on. So, bottom line. Find a way to give yourself a long term interest in keeping going with the software. No better opportunity than the myriad of projects that people start here.
In the video above, the part were he talks about wanting to highlight a part of her neck with light is great. Now, he just wanted to do that as someone that looks at the form of the body a lot, he was convinced to show that part of the body more was better. I don't know if it was better. However, it made the image look strange. And I'm all about that, some strangeness catching the viewers attention.