I see no signs of ADHD, and if there are any, they are very minor, so yes that is absolutely a minor concern compared to him being a raving malignant narcissist.
If you see Trump speeches from 40 years ago, it is very evident that he does NOT have ADHD, back then he was perfectly coherent and could stay on track for hours. People with ADHD cannot do that.

The fact that he can’t do it now, doesn’t mean he has ADHD it means he has dementia.