I highly suggest you read about the subject. This isn't the fringe science you're implying. It's a big reason I was diagnosed by my doctor. And it's often treated quite well by taking ADHD medications.
“While the estimated 8 million adults in the USA affected by attention-deficit/hyperactivity disorder (ADHD) might find it nearly impossible to sit still in a lecture hall or excruciatingly challenging to focus on writing a term paper, these same individuals might find themselves spending hours at a time composing a new song, tinkering with their car, writing computer code, or watching television (Kessler et al., 2006). The term “hyperfocus” (HF) has been used to characterize this state of heightened, focused attention that individuals with ADHD frequently report (Brown, 2005; Conner, 1994; Ozel-Kizil et al., 2016).”[1]
[1]
https://pubmed.ncbi.nlm.nih.gov/30267329/
Other reading:
https://pubmed.ncbi.nlm.nih.gov/30267329/
https://pmc.ncbi.nlm.nih.gov/articles/PMC12438511/