Is there a way to change the linework that Revit creates when you cut cross sections?
Yes. This is exactly the purpose for the Cut Profile tool (located in the Graphics panel of the View ribbon). For example, when you create a cross section through a building with a sloped roof, Revit shows a basic junction between the top of the wall and the roof, but that junction probably doesn’t look exactly the way it should. You can use the Cut Profile tool to modify the appearance of this junction. Note that you aren’t actually changing the model, just altering its appearance in the particular view. Here’s how it works:
1. After creating the section, click the Cut Profile tool.
2. On the Options bar, select either Face or Boundary between Faces.
3. Hover over what you want to edit until it highlights, and then click to select it. Revit switches to sketch mode.
4. Using the sketch tools, sketch the change you wish to make to the profile. Note that the lines you sketch must connect to the original profile. You can also control what gets added or subtracted from the original profile by controlling which side of the lines you wish to keep. When finished, click Finish Edit Mode. If the results are not what you wanted, you can select the cut profile and then click Edit Sketch to go back into sketch mode to make additional changes.