It forces me to read everything as though I'm reading Shakespeare, except the cadence never really comes. Now I feel itchy and angry at my monitor for showing me this
I feel like you'd be able to tell from the screenshot, if it has an effect on you.
My brain tends to overanalyze individual words, which is great for spotting typos, but awful for reading speeds. This highlighting feels like it helps my brain to quickly go from word to word, and not get stuck on them.
Reading the comments on some reddit posts, it seems like it matters how your brain handles words - like there's different types of ADD/ADHD with respect to reading (which I guess makes sense considering inattentive ADHD vs hyperactive).
Just reading some examples, for me it seems to help keep my brain on track and continue reading the words, instead of normally skipping words, losing your place, and requiring to reread the paragraph.
the thing where it actually helps is if you're "one word speed reading" (eg. http://onewordreader.com/). Then it's easier to rapidly focus your eyes on each word, without having to follow a rigid timer. But if you're reading normally it probably doesn't help