What does selective++ mean? I would expect the deadlines for most schools that you mentioned on your prior thread have passed for Fall 2025, as well as any school that is an IB target school.
Would your S consider Spring 2025 transfer, and either take a gap semester, or return to current school for one semester? What has changed since your last thread:
Undergrad business programs?
The NACAC list is a good start, but there are many more schools still taking transfer apps, generally not schools with say below 30% acceptance rates though. Have your kid also look in the common app transfer app (you can filter by deadline date) and/or the school’s self app. And yes, they might have to call to see if they are still accepting apps.
SMU and IU look to be open for transfer apps for Fall. You might try Bentley too and see if they have room (deadline was April 1)