I think you can do similar things in ArchiCAD.
You can create a Guide Line.
Then you can create other Guide Lines that are perpendicular to this Guide Line. You can even use the Special Snap Points to set intervals.
E.g. I could draw a horizontal Guide Line Segment of 5 meters.
Then I could set Special Snap Points to "Distance" and set 1 meters for Distance.
Then I could go from one end of the drawn Guide Line, the Snap Point appears at 1 meter from its end and I can create another Guide Lines perpendicular to my first Guide Lines. Then I can create additional ones similarly.
Is this what you try to do?
About edges of GDL objects: there is a GDL command called HOTLINE2. If there is a HOTLINE2 command the line drawn by that command will be sensed by the cursor as a line when the object is placed.
So the library parts can be written to have this intelligence.
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