How is your interaction so limited with attendings? Is it mainly resident driven? If so, you'll need to step up and tell the residents this is your field, and you want to own the rotation. Ask them for help, and be (semi)aggressive in having them let you present to attendings. The key here is initiative. I've been on rotations where I mainly interact with residents, it can be hard to get too evals/LORs.
Another little tip for looking good: What I tend to do a bit is read up on the patients, then ask questions I technically already know. You can always sneak in a subtle expansion or clarification to show your understanding and knowledge. If the attending gives you the "half-smile" and asks, "Why don't you tell me?" that's your chance to show off a little knowledge. In my opinion, it's simply good strategy. And it teaches you along the way, too. 🙂