I don't know how to keep the DRLs on at full brightness when the headlights are active.
Some clever rewiring should be able to accomplish that.
That being said, the Stinger has pretty good headlights.
However, there have been many instances of these cars being delivered with aim that fails to light the road as best as it could.
It sounds like your car would benefit from raising the headlights aim upward a bit.
There are posts here on the forum that will help you do it yourself. Or you can have your dealer do it for you.
Also, be sure to try the headlights in the AUTO setting to get the full benefits they have to offer.
You'll likely find that you don't need the DRLs for additional light after proper aim.