Few more things… at first when turning on the Grid, the default *shown* Grid size is 20×20, but sometimes the Grid is actually on a smaller scale. That’s a tiny bug. So when you turn on the Grid I suggest you change the Grid size to say 5×5 and then change it back to 20×20 just to make sure it is really set to 20×20.
Working with the Snap options is very useful. Both Snap to Grid and Snap to SX help a lot to make the work smooth.
The Snap to Grid is “stronger” than the Snap to SX though, so when both are toggled on, the Nodes will tend to snap to the Grid over the SX, so when drawing or changing Nodes links to SXs, it is better to toggle the Snap to Grid off!
Toggle it on again when snapping to the Grid is needed.