The "reference bitmap" on the back of the designer view in the studio is greatly limited by not reacting to the scaling percentage on the development workstation.

If your dev workstation is at 150%, then the grid is not going to show you anything of any use, when trying to design a layout that works on a smaller screen, at 100% magnification.

(having a physically smaller 4K monitor, developing at 100% isn't a viable solution either).

MM