i think this is where a software should do its role, by automatically avoiding this confusion or notifying user. accidentally snapping origin to this 'off the grid' pad will screw the alignment and diptrace failed to notify this to the user. now to the non-aligned pad, sometime we are constrained by real life components that are not metric or imperial aligned, so we 'll need to design pattern or footprint that is off the grid, but when we place on pcb we need them to be metric aligned.

the only way that can make a component be off the grid is using manual XY input or snap 'enable' or 'disable' which the user should be intentionally or aware by clicking that feature. so it will not counterfeit the 'snap to grid' features.

Thats why i proposed to diptrace team so the app will use its own grid reference system, by saying that it means whenever i try to change origin to a non-aligned pad/component etc the origin will not snap exactly to that non-aligned coordinate, but snap to the closest grid of diptrace's reference coordinate system.

Diptrace 2.3 registration key