Exactly. All 3 of my kids had to decide which meaningful things to leave out of the list of 10 but the one who applied to the UCs didn’t use all 20. Providing more options becomes itself a test of the students judgment that the colleges can decide to consider or not. If someone has 20 slots uses them all, filling some with silly or trivial things, that is a fair reflection on them. If another person has 14 things that the AO all finds relevant, good for them.