If they are tight enough then there should be some carryover, and obviously the thickest sleeves will add the most. I have a pair of grey Rehband sleeves that I bought when I was having some tendinitis issues a couple years ago, I stopped using them because I realized that they added about 10lbs. to my bench. They are pretty tight though, they have stretched a bit but I only use them for squatting now. Also, I was using a fairly close grip at that time, it makes sense that more elbow flexion would get you more out of the sleeves. Keep in mind that these are some of the thinnest sleeves on the market too, the part on the outside of the joint is 5mm and the inside is 3mm. I know that some people say that you get nothing out of elbow sleeves but that is my experience, if you aren’t trying to cheat then I would recommend getting a loose pair.
I have heard of meets in the olden days that allowed people to wrap their elbows, is that allowed here? Also, Inzer makes sleeves (elbow and knee) that appear to be made out of wrap material and are adjustable, I’m sure that you would get something out of those if you pulled them as tight as possible.