Hi!
Originally I designed the TATE Mode on Switch for the FlipGrip addon, which only supports one orientation. I later added support for both modes in a PC-only update.
I've been hoping to release a patch for the Switch version to bring it up to date and add some other improvements, but unfortunately I just haven't had the time since then due to about a billion other commitments.
The code to support both orientations now exists in the project though, so if and when I do get round to updating the Switch version it will be included.
Sorry for the inconvenience there, and thanks for buying the game multiple times!