Thank you for your response and video.

I was simply wondering how others would approach the problem presented. The solution I posted uses line work drawn with the correct slope and then converted into a design line and filled with 3D pipe and fittings.  I find laying out the sloped line work (I use an add-in) and then converting to Design Lines works very well.  The line work isn't generating any of the errors I have experienced with design lines and I can lay everything out, save the layout, and then generate the Design Lines.  Making modifications to existing sloped systems is easier and I can preview the sloped pipe path right from the start.

I am having a problem getting the Quarter Bend to automatically place - a short sweep keeps appearing instead. It looks like you are getting a short sweep  in your video as well (the upper elbow appears to have the same distance from coupling to center as the lower elbow).

If you are interested, I can generate a short video illustrating my posted solution.