TATE Mode is a vertical mode exclusive to the Switch, sorry!
I was talking about the Switch version the whole time. Which is why I referenced the company that published that version. This was just the only place I knew I could contact the original dev, as I'm sure they'd want to see the port be the best it can be and could probably help coerce the publisher to do something about it. (Incidentally, Summitsphere did respond that they'd be fixing it.)