The original thread was to solicit users for an efficient procedural solution to the hypothetical sloped pipe installation. 

The entire run is sloped, so unless I am mistaken, using multi point fill requires determining the selecting points based on the specified slope before the fill can be started. Determining the points could be accomplished by adding a design line and then applying slope. The alternative shown routing a 3D line complete with the required slope first and then using the Trace command the design line is added and populated.

The last item was that the design line was populating all elbow locations with a short sweep when a quarter bend was requested for the highest elbow location (short sweep at the other locations).  You can replace the short sweep with a quarter bend at that location using multi point fill but it seems to be a very inefficient method given the number of mouse clicks involved .