This Brio and Ikea compatible reversable piece of track swerves one track width to the side. I have included two lengths.
The 150mm (6 inch) piece is about as short as it can be while still having the curves be gradual enough to allow trains to pass easily.
The 200mm (8 inch) piece is as large as possible while still fitting on a Prusa Mini print bed in one piece, albeit without a skirt.
Also feel free to check out my other train related items: