Still, this does not help because:
1. If I set small size of grid, like 1 cm, it's not fast enough to get orthogonal line. This has to be like fraction of a second, you know. Thousands of lines to draw at every project.
2. If I set larger size of grid, like 50 cm and I type dimension like 45 cm, I'm already off grid, so my next line, starting from first line's end, will snap to absolute grid instead of staying orthogonal, as it would do in AutoCAD.
That's why I find it worth adding such an option like "permanent orthogonal drawing", equivalent to AutoCAD's F8 key.