I don't see the rotation code in it, but it's easy to add.
I hadn't try swanstation for a while, so I did this morning and went into some issues like having the screen upside down, forcing video.hw.bottom_left_origin to false in video.c fixed it for me.
I got another issue about inputs, but maybe this one happens only on m1 mac.
About the upscaling, it appears that there is something special in the option names of swanstation and I may need to add some more code to support it in swanstation.