Unless at least one of these is going to tell a lot more about him, than his other LoRs, the proper course would be to send neither. Otherwise, no more than one - whichever has the most unique and helpful info.
Following up: apparently it wasn’t too much b/c DS got a YES-W invitation… Of course, that might have been in spite of the two supplementals (which he had already arranged for by the time I got the CC answers). I am willing to believe that the letters were annoying but not sufficient reason to reject, if @gibby tells me so!
^ I’m glad it didn’t hurt your son, but I also wouldn’t have recommended sending 2 supplemental letters. In general, 1 supplement at most is accepted by schools, and only if it adds a new perspective or information. The research letter sounds like it would have qualified. The arts teacher not so much. Being “generally a helpful guy” isn’t enough. Submitting an arts supplement showing your son’s work would have been acceptable.
By making that limitation, they are not considering the situation the kids are in trying to get these letters. My daughter had no good sophomore letter options except one teacher who also taught her junior year and liked her work a lot, so that one was obvious. For the second one, she chose the next best junior year option, but not someone who would write an amazing letter. She asked for the letters in the first week of school senior year. In December of her senior year, one of her senior year teachers asked to write a letter because he liked her a lot and she was doing really well in the class, so she got a third letter, but she had already put the first two on the common app and it went out that way. So the third teacher mailed it in. Meanwhile, a mentor from an activity outside school asked to write a letter and sent it to all her schools including Yale, so she has now submitted 3 teacher recs and an outside one. Now I doubt she will get in anyways, but if she doesn’t, I hope she isn’t rejected because a teacher and a mentor outside class both really wanted to write her late strong recommendation letters.
^ I think unsolicited letters are treated differently. No one can stop a teacher or other person who knows an applicant from sending a letter on their own. I had that happen, a long time ago - a teacher who knew me really well outside of the classroom chose to send an unsolicited letter. It was an amazing letter, and I’m pretty sure it helped.
I think it’s probably a good practice for anyone choosing to do this to identify that their letter is unsolicited. I think any time a teacher asks to write a letter because he/she feels strongly about an applicant, it sends a positive message.
b/c DS got a YES-W invitation… Of course, that might have been in spite of the two supplementals (which he had already arranged for by the time I got the CC answers). I am willing to believe that the letters were annoying but not sufficient reason to reject, if