I promise you that we all feel your pain on this. All of us had multiple repeaters, and locks that worked flawlessly on other hubs like Wink before migrating to Hubitat. It caused us a lot of frustration and the only thing that has so far worked semi-reliably was adding a bunch of Aeotec Repeaters. Try to have a minimum of 2 - with one of them as close as possible to your hub, and the other as close as possible to your lock.
Prior to adding repeaters, I had about 15 z-wave plus devices in my small home. All capable of beaming. One of them was 3 feet from my lock. Yet I had super flaky behavior until I got the repeaters. You have a lot of empathy in this thread, I assure you.
However, now that the HE team has acknowledged there is indeed an issue, a lot of us are very hopeful that we will see a big performance boost with the next major code update (2.1.1) when the Schlage specific driver is released. The HE staff has been pretty great at fixing things and being responsive, they just have a long list of things they are trying to work on and they are still a small and growing company. I am willing to be patient with them as the Aeotec repeaters make my locks work 95% of the time, and I am confident that the HE team will take care of us as soon as they can.