Law is definitely the biggest believer in his upside I think but he tends to favor ceiling over floor in his rankings. In his midseason update he had him at 27.
"Alcántara has held steady this year as a 21-year-old (by his seasonal age) in Double A, keeping his strikeout rate low for a 6-6 hitter and making hard contact without a ton of game power yet, with plenty of projection remaining on his frame. He just turned 22 last week, so he’s right on track with college juniors drafted last year, a large number of whom are in Double A as well, but offers a wider range of potential outcomes with first-round upside if he keeps the contact rate steady as he fills out."