not completely sure that it would be pointless to send in updates...
during my interview day, REL stated that they sometimes dont choose the top of the list. this was mainly to try and maintain their 20% OOS ratio, but i would think that a significant update (such as a publication, or medical mission trip, versus just transcripts) might help you jump a spot or two in favor, without the admissions committee actually rescoring you. this is just speculation based on the fact that they do not use absolute guidelines for choosing applicants off of the "wait" list. REL or anybody with better info please correct me if im wrong.
i was speaking to REL about an update that I intend to send. since i am taking a year off, i am currently doing clinical research/shadowing with an emergency medicine physician, i plan on adding another letter to my file. since i have no new grades and cannot maintain/improve on the leadership roles i held during undergrad, this would be a significant update to my application. he encouraged me to send it in prior to my admission committee review date (post-interview). SO if you do have updates, they are most useful to the committee before they actually score you. but i wouldnt say there is no point in submitting, so if u guys have something worthwhile to say, then say it!
i too was curious about the potential overlap in applicant scores. since the maximum score is 70, i assume that many students score between 40-60 (3x14= 42, 4x14 = 56). If they have to choose a student out of maybe 5 students that share the same score, they may prefer students based on their IS/OOS classification, racial/gender diversity, interest in UCF, or significant post-review updates. if it were very late in the cycle, they may choose the "waitlisted" applicant who is most similar to the accepted applicant who gave up the spot, just to maintain class diversity and what the accepted person might have brought to the incoming class.
again, more speculation on my part, but it would be how i would operate if i were on the admissions committee. 👍