How long does it take to adjust to an ergonomic keyboard?

Most people adjust to a curved keyboard in 1-2 days. Fully split columnar layouts take 2-4 weeks to reach full speed.

Do ergonomic keyboards help carpal tunnel?

They reduce the wrist positions that contribute to carpal tunnel syndrome. They are not a cure but can significantly reduce symptoms and prevent progression.

Best Ergonomic Keyboards for Typing Comfort