If you're mission-critical then your company has a bus factor of 1, so you probably should make sure that other people know how to fill in for you. Then you can

If you're mission-critical then your company has a bus factor of 1, so you probably should make sure that other people know how to fill in for you. Then you can take PTO and tell people to look at it as a training exercise just in case you do get hit by that bus (or, you know, quit because you're burned out).