Yeah, usually it's only noticeable when highlighting damagelogs. But even then, it's still somewhat legible at times. If you're still concerned about logs being blurry, what I usually do is highlight the logs outside of what needs to be screenshotted. So 1 line above, and 1 line below.
Alternatively if you're looking for screencapping software, gyazo is pretty solid.
Alternatively if you're looking for screencapping software, gyazo is pretty solid.