Landmark does help with ADHD but is exclusively for kids with learning challenges. The college is a good resource though with a summer progrm, with preparation for college, and gives names for good coaches. ADHD coaching is pricey but helpful.
I thought of Curry, College of New England, Lesley, and Endicott in addition to what others have mentioned.
My kid with some of these challenges, did p/t college eventually- at Lesley’s adult learner program- with one on one support! My kid is bright but has severe ADHD. Just saying, things can work out over time if a first try doesn’t pan out (They first went to Bennington.)
Later on, there are many degree completion/adult learner degree programs with lower admission criteria.
Your kid sounds bright but not a good test taker. So going test optional or test blind seems like a good idea!