Can bathroom exhauted fans and toilet vent share the same roof plashing?
Totally against Code, and extremely dangerous. I have always preferred an exhaust fan to exit out the side of a building, rather than the roof. The moisture has to fight to get out of the roof level. I always run solid ducts (no flex ducts) and pitch them downwards towards the outside of the building. Been calling them Fart Fans for years.
If you have never made a mistake, you haven't done much.