I think part of what many of us are telling you is that a lot of AIs aren’t going to know or care who wrote a letter of recommendation or the scope of your research. If it’s that great, your GC should be mentioning it or if it’s truly earth shaking, the AO might know because many of them keep tabs on these things. They also know the professors at their college.
The thing is, you don’t just send in a LOR. Anyone can write one and send it. For it to be considered part of the application , it is so submitted. You can ask that professor if he’ll do that for you, not just email or write a letter saying how great you are. The teacher and school LORs are accompanied by information as to who they are and info to verify it it’s easy to write a letter of shoot an email over to admissions for someone. Heck, DH snd I are asked every year if we’d do that for our alma maters. As are alums from nearly any school, especially for selective schools. So AOs get tons of these notes. But if it’s channeled through the Common Application it supplement that a school provides, it’s a whole other story. Unsolicited material to Admissions often gets little attention.
Now, we are all saying this when you could be the next a Elon Musk or Bill Gates or whoever. Perhaps your research is stupendous and you drove it. If that’s the case, the professor should be more than happy to personally approach admissions at his school and have you on his team. Something like that could be a game changer. Yes, it happens, but rarely. If you are one of those rarities, that research prof would be glad to personally take your case to Admissions. But to another school? Ummm…you can talk to the prof. Probably will tell you that s/he doesn’t have a whole lot of clout there, but here’s a letter and you figure out how to submit it.
Also, sometimes serendipity comes into the picture and any essay, EC , subject, research can hit an AI the right (or wrong way). One of mine lucked out with a terrible essay on a boring subject more like a research paper that hit his AO perfectly—so perfectly that he got a handwritten comment about it on his acceptance letter. These things can and do happen.
So give it your best, but don’t count on it. Research safety schools so that you have good strong choices in that department. But , go on ahead and play the lottery.