Roof frame family

What is the best method to create a roof frame family that can quickly be dropped in to a model and align to the slope of the adjacent framing. What I'm looking for are small roof openings with steel angle frames, larger openings with channels, mechanical platforms with channels or beams that sit on top of the roof framing etc. Doing these individually is just too tedious with rotating/adjusting the placement of each member to the correct orientation- but it does attach to the sloped framing. There are so many roof types in play (flat, mono-sloped, warped; individual members, beam systems, imported from RAM...) that I think the best way to approach it is by selecting the adjacent framing not a work plane or roof to place the frames.

I am searching for the same answer and came across this post. Guess no one is willing to share?

This is roof opening frame using angles to share with others.
can be placed on face of sloped roof or on flat level. use offset to adjust elevation.
used instance parameters to adjust location of opening and span. You can drag on screen or adjust with properties.
angles shown as line work in coarse view, use beam family to place. the angle sizes are not parametric.