How often do checkmate patterns show up on the board?

Some patterns are rare, while others happen with great frequency. All are well-worth your time learning. I don’t know about Raf Mesotten's book, but I have some excellent books on checkmate patterns and have found they have helped my game. The best books IMHO are The Art of the Checkmate by Georges Renaud and Victor Kahn, and 1000 Checkmate Combinations by Victor Henkin. The latter is not only a checkmate pattern book, but in many ways a complete course on tactics.
This guy’s reviews are a useful guide:
http://chessskill.blogspot.com/2021/11/learning-checkmate-or-teaching-it.html
http://chessskill.blogspot.com/2022/02/two-old-books-and-one-new.html

It depends on what you mean by "show up on board". Does it count if the opponent has to choose between being smothered mated, being epaulette mated, or enter a lost ending?