MDSHA would most likely create them and provide a DGNLIB for you to use. It may be worth bringing it to their attention so they can get started. I am not sure if you saw the videos from the link below that address some of your workflow for creating Feature Definitions in SUDA
communities.bentley.com/.../12600.subsurface-utility-engineering-sue-support-clips-technotes-faqs
also you may want to visit our Learn site. There are links to training at the wiki article below
communities.bentley.com/.../27341.openroads-training
communities.bentley.com/.../12600.subsurface-utility-engineering-sue-support-clips-technotes-faqs
also you may want to visit our Learn site. There are links to training at the wiki article below
communities.bentley.com/.../27341.openroads-training