I would seperate singles and doubles.
In singles, it sounds like this guy does not S&V. If he does, he is likely vulnerable to a pass DTL, which I would not slice as it would likely sit up if he did manage to get a racquet on it. Much more likely he is a baseliner. As such I would go CC, since shots DTL need to be winners, since he has an easy CC shot to the opposite side that you are going to be out of position to get to. You probably already know that, which is why you are hitting 50% of your DTL shots out/in the net, ie you are going for winners (which you should be on that side of the court). Trouble is you aren't currently able to pull off the shot. Go CC, a slice is fine. Now he is faced with the problem you were a minute ago: do I try for a DTL winner (maybe he'll hit 50% of them out/in the net like you did) or do I go CC again, which BTW will be right to where you are standing, perhaps for an inside in FH winner.
Doubles is a different story. Many if not most netmen wll not shift to cover the alley on a wide serve, the answer is easy, DTL topspin winner into the alley. After a couple of those, the server will either stop hitting wide serves, or the netman will shift to the alley, which opens up the middle of the court from poaches, a much easier shot for you.