Maybe this has already been suggested...
I know that there are sketch-based arrangements/patterns. But it would be so much easier to do such a thing in a dialog box. Similar to the existing box, but wihout the amount of numbers and distance fields. With every enter there would be a new input field, until you stop. So the first distance could be 100, the second 246, the third 195, etc.
The result could be handled like the pattern we know - as one object in the model browser.