Sorry, you'd dropped off my TIO.
DS2 now has his shortlist of 5.
He was not able to visit one of these (was not possible to get to the open day) but it meets all his criteria so he will apply unseen; if he gets an offer he can visit it on an offer-holder day.
He is currently at the same summer school as gospa's DS. There are only 35ish students, so they probably will have met each other. He applied by participating in an online physics challenge, open to anyone in Y12.
He didn't apply for Sutton Trust or UNIQ as he doesn't meet enough of the eligibility criteria.