I have noticed that quite a lot of people position parts in CAM in the positive quadrant of the Cartesian plane. It makes a lot of calculation and planning easy so it makes sense.
When you place a vise square on the table the moving jaw to accommodate different size stock is in the negative direction usually. This requires touching off and relocating ZERO for Y a requirement for every single job or part of a job after rotating a part. Even those that don't require a huge amount of precision.
The obvious solution is to design a vise with the screw drive on the other end positioning the moveable jaw in the positive direction.
The less obvious but much easier solution, is to work in the X+ Y- quadrant or move your work to X+ Y- quadrant after you have done all your calculations, layout, and planning.
(FYI: I tend to work with XY ZERO in the center of my stock because I do a lot of rotations around an axis and/or symmetrical work, then I move my work to the positive quadrant so I can just touch off rather than touch off and calculate.)
I was trying to develop some work processes that allow me to do certain types of jobs and setups faster, but then after typing all this it occurred to me that for most of you guys its probably all mind numbingly obvious. LOL.