Par4QC
Oh, got it. I was told not to cup when I first started playing in the ‘90s. Wanted to get rid of my slice, and so I definitely practiced it (along with fixing my swing path). Eventually I became a hook machine and I stopped purposely trying to flatten the wrist.
Interestingly, I stopped playing regular golf for about 12 years (because of time, kids, expense, etc.). Picked it up again in 2018, but rarely fade/slice, so cupping is not something I thought about. I do not see cupping when I look at my swing on video, so I guess it was ingrained.
The biggest change I found when picking up golf again is lost distance.