I did the b&b for our Barndo. Hopefully they have made it a bit more rigid to compensate the “oil canning” effect. I love the look of it but it has various states depending on the temperature. When it’s really cold, I have “dimples” in mine that are conforming to the girts. I’m not particularly happy with what it’s doing but the landscaping will soon hide it and most people don’t notice. More on reddit.com

I prefer hardie. I left a couple pieces laying soaking on my deck over a Canadian winter and then put them back on the house in the spring. A little fragile at first, but now I can't tell which ones they were. Dust is an issue, and installation is big since you can put up full sheets with fewer breaks in the siding. Get a nibbler if dust is a big concern. More on reddit.com

My house in the pnw, never had to paint hardie plank again. Looked just as good 14 years after I bought the place. When I had a garage then adu built I went with hardie again. More on reddit.com

I assume the thermo properties of dark metal siding are mostly negated by good insulation, but you should look into that. Those galvanized metal grain bins you see in cornland are about 40° F hotter than the ambient air temp when sunny. Obviously they aren't insulated but dang do they heat up. I think it looks pretty good when done right, I like the industrial look. Cosmetically, your design would need as much sensible visual breaks in the siding as possible, as to avoid it looking like a straight up pole barn. Windows with contrasting trim like your example pic, gables, etc. Anything to help give a design statement that borrows the siding element from a shed, not becoming a shed. More on reddit.com