As Sunil said, the LMB are still there. First thing I would do would get a better grip on who is calling the pond home. Keep fishing. As often as possible and using as many methods as possible. Document your findings. Post those here for a more clear plan. I wouldn't want to invest money into a pond before knowing as much as possible about it first.

I agree with Sunil that feeding even "only" 4-5 times a week will be beneficial to your HSB's growth rates. I would consider focusing on one location to feed and try to feed at or near the same times of day when you visit. Get them used to it and they'll come to expect it.

Welcome to Pond Boss KB! You have certainly found the right place for your questions.