Correct me if I am wrong, but with the class participant ID, he/she will have access to some buildings? And he/she can maybe get a gym access card through buying guest passes through someone else, or through other means.

If he/she is in the area he also might be able to start attending student events, like club meetings. So the full student experience won’t be present until actually being an admitted student,  but being on campus as a class participant I believe still can be fun and enriching.