If your wrists are digging into the edge of the case, you are setting yourself up for repetitive stain injury, irrespective of the case edge shape. You should

If your wrists are digging into the edge of the case, you are setting yourself up for repetitive stain injury, irrespective of the case edge shape. You should be orienting your keyboard/body in such a way that your forearms are approximately parallel to the keyboard surface, and most importantly so that your wrists are as straight as possible. If your wrists are more than slightly flexed (or extended for that matter) injury is waiting just around the corner, and finger strength and speed is undermined. Look at any expert tool user, especially tools requiring finger motion (e.g. musical instruments), and you will see they largely keep their wrists quite straight. Ideally wrists/palms should be “floating” freely above the keyboard, held up by your arm muscles or possibly light fingertip pressure on the keys, with your upper arms roughly parallel to your body and your shoulders relaxed. But if you lightly rest your palms on the laptop surface that probably isn’t the end of the world, as long as your wrists remain straight. Typical desk/table and chair heights are poorly adapted to typing on a flat keyboard. A table which is the right height for handwriting or eating is generally too tall for typing. To compensate (assuming you aren’t willing to get a lower desk or taller chair or put the keyboard on your lap or a low tray) I recommend tilting the back end of your keyboard up (e.g. by piling something underneath) until the keyboard surface is parallel to your forearms when you place your fingers on the keys. For inspiration, look at the slope between keytops of mid 20th century typewriter keyboards, which are built to fit in with typical office furniture. Once you get your body/tools into a more appropriate pose, your typing will be faster and more comfortable.