Yes. he knows he cheats at golf. Other players have observed it and commented on it numerous times in the past.

Here the thing… Golf is a sport you play against yourself. Nothing another player does can impact your score. It’s a game of precision, consistency, and dedication. At the end of the day, nobody really gives a fuck about what your score was except you. You play to improve yourself. Cheating at golf is cheating at self improvement. Pun intended, Trump cheating at golf is par for the course, and it neatly sums up everything wrong with his personality.