@2mrmagoo I think this is a myth. Certainly my college has no pathway for such a IMHO inconsequential data point to a kid’s application. Colleges are already having to beg and plead with alumni volunteers to get them to interview at all – given the high rates of rejected kids. To infuse the importance of a Thank You note into the interviewer’s mind would be crazy.
If my college asked me and my area volunteers to do that, I’d have some sharp words with them. “Read my d*** reports and recommendations. Don’t log thank you notes!”