There is a review of this event from last year in the 2018 national merit thread on the National Merit scholarship subforum. There is also a mention of the March event for finalists.
November: http://talk.collegeconfidential.com/national-merit-scholarships/2057290-updates-and-info-for-those-students-looking-to-become-nms-with-the-ucf-golden-knights-fall-2018-p1.html (I think it is on pg 2 or 3)
March: http://talk.collegeconfidential.com/national-merit-scholarships/2008875-2018-national-merit-finalist-thread-p21.html (keepscrolling down)
There seem to be a few students or parents on the NM subforum who either are interested or already attend UCF.
I have not seen the offer to pay for the visit mentioned anywhere, however. Good luck!