As another person with ADHD, doing something like this but on a way smaller scale, incrementally with longer period of times (I'm up to something like 20 minute

As another person with ADHD, doing something like this but on a way smaller scale, incrementally with longer period of times (I'm up to something like 20 minutes after years of doing this... Started with doing just 1 minute per time) helps me cope when I'm forced to do nothing, like waiting, which I absolutely hate doing. See it as an exercise, where you'll become stronger over time.