If a school , whether it’s your highschool or college has a channel for your research description, LOR, go right on ahead and use it. If a school does not have any such channel, don’t, is my advice. As I stated before, it’s not like you just send the LORs; there is standard info that is requested from the reference.
Many schools have a procedure for students to send in supplementary material. If you really feel like your research will elicit ahs and awe from the Admissions office, go on a head and send what you think is so awesome.
Can it look BAD? Yeah, if poorly done and you have the wrong impression on how great thou art and it strikes the AOs wrong. Usually, no. It won’t make a difference most of the time unless you win the Intel or Siemans or other known national award for your work.
By personal channel, I mean that if the professor who is writing you this rec , is known to the AO, and personally reaches out to Admissions, yes, it could make a difference. Admissions at selective colleges get thousands of letters from “important” people, and unless there is some action to differentiate your letter from the pack, it goes to the same place as most do. A simple reference letter isn’t going to do it. A visit to Admissions and a talk with the AO or a phone call could. If that professor wants you at his college, and he personally discusses this with AO, it could make a difference. A generic good reference won’t.
I am writing this not knowing if you are possibly the Second Coming in a field of study. If you are, you have to get that message through to an AO who will be glancing through your application likely summarized on some form. Unless it’s flagged as celebrity worthy or special request from professor, it’s not likely to get much attention. Trust me, it seemed like everyone had an “in” with a reference from some donor, alum, prof, someone important when my kids were applying to college. If the “in” was that powerful, it wasn’t discussed ; it was just known. Many disappointed kids who thought being published, working on some project was going to turn the AO’s Head.
Really, if you feel it’s a game changer for you and you are going to always wonder; it’s going to bother you if you don’t send the info to AO, go on ahead.