Justice League #10 introduced Jarro, "Starro in a jar", born of a fragment of Starro, who died in Justice League: No Justice #3 (2018).
Jarro is mainly monitored by Batman, and no other Justice League member seems to be baffled by his presence. Even more, Batman (and no other Leaguer, but most importantly Batman) does not seem to be the least worried about having this kind of telepathy/mind control power running around free, with no sort of control. Admittedly Jarro has behaved with good intentions so far, but so did every superhero in the DC universe and Batman stays wary of whatever harm might come from their powers, notoriously having contingency plans for most of them (Green Arrow excepted).
Actually, issue #29 of Justice League (2019) demonstrated how powerful Jarro was already, with him being able to mind-control the whole League. Batman gives him a pep talk, a hug and no more mention is made of the incident.
This leaves me baffled. If anything, I'd have expected Batman to become super doubtful of Jarro after that, not treat him like a regular kid who made a goofy mistake. Furthermore with the out-of-character behaviour, Batman lets Jarro call him "Dad", "Pop", stay on his shoulder, treating him as a son/pet when he never demonstrated this kind of affection (in such a public, lasting way) for anyone, including the Robins, especially Damian.
Now obviously Batman is in a bad place these days after
Alfred's death in Batman #77 (2019),
but the opening of Detective Comics #1017 (2019) makes it clear he wasn't even there to provide Damian with some emotional support
and Damian definitely needs some, more than Jarro, as Bane killed Alfred in front of him.
Why then is Batman, who's now "more brood than man", acting so out-of-character with Jarro? Why does a newly-introduced, potential conqueror psychic starfish get more love and leeway from the most paranoid guy in the DC universe than anyone else? Is it simply a writing choice to play on the "cute" string or is there more at play here?
Bonus related question: does Batman have a contingency plan for Jarro?