Finishing an attic, building codes, layout possibilities
You say you don’t like answers that start with, “...the Code says...”, but I say, the Code says, “Habitable rooms, hallways and basements containing habitable spaces shall have a ceiling height of 7’ min. (ICC R305)

Also, it says, “ For rooms with sloped ceilings, the required floor area of the room shall have a ceiling height of not less than 5’ and not less than 50% shall have a ceiling height of 7’.”

It also says, “Conversion of basements and attics to habitable space shall provide a minimum height of 6’-8”.”

I’d quit arguing with people and go see your local Building Official and get a copy of Section 305 AND read it yourself. Talk to him/her. They’re there to help. (You’re getting a Building Permit, right?)

Maybe you can furr out the side walls to 5’ and make a great “habitable room” with bookcases, shelving, etc. along the walls. (Bathrooms, etc. is 6’-8” and showers are 6’ minimum height.)