The fact that he is looking for a lower house edge, that means he believe that his chances of winning would increase.
Regarding this, this minimal reduction is not going to change anything in the long term results, because House Edge will continue to be a loser, and in the short term, well, having 0.5% more in his favor will make him have some more positive sessions and will last a little longer, but I don't think he is going to notice it much either.
If he is looking to “make money” playing slots by reducing HE he is taking the wrong approach.
I'm sorry but I think it is. When it comes to House Edge, I think that even a tiny decrease or increase on it can mean a lot already or we can say that it is a game changer. Also, I think it wasn't the House Edge is the ones that is the loser here or will continue to be a loser as you said because House Edge is an ally of the casino owner. It is known that they always win, especially in the long run that the gamblers are playing.
Even with what I've said earlier, there are still better games than Slots that already has a default lower House Edge if we want to make money but there is still a better advice than it, and that is to not see gambling as a money-making machine.