I like your project! Thanks you share it!
At this moment the plugin can't make roof with edges at different elevations.
I work on this but it's not so simple.
For a multiple levels roof you have to generate multiple roofs.
I've prepared a tutorial for such case because I've needed too.
Is not finished yet but could be used as principle.
Unfortunately is not exactly what you need.
https://www.mediafire.com/file/apcarz1v ... 3.pdf/file
https://www.mediafire.com/file/mbuc6xlg ... .sh3d/file