Is there a way to increase infill, just around area, the will have screw inserted into in. Not to increase infill thought out the entire project, just the desired area.
You probably want to look into modifiers. And maybe focus on an increased wall count rather than infill.
I just did this.I added the circylindar modifer and a few extra walls and placed them around the holes I designed for my piece. It worked perfectly. I ended up with a built-in washer look to my piece. If you don’t want to see it, I would change the height so it starts up a layer or two and stops a few layers short of the top. That way, you don’t see it. I have a circular pattern on the top and bottom, then the rest of the lines run diagonally. As I wouldn’t see it, it didn’t bother me. But it is something to think about if you see it.