What weight do universities put on high school grades for transfers who are applying into the spring for sophomore year with 30+ credits already under their belts?
Typically none. A lot of schools don’t even request a high school transcript if your classes will transfer(though they may want proof of your diploma). The only issue is if there is no articulation agreement between your schools and you’re basically transferring in as a “Freshman” until all your credits get approved by the registrar and you get bumped back to a Sophomore.