Never loved all the metal on the KillDeer. It's also very spendy for a treestand rock harness.
I've been using a rock harness since the late 00s and never felt a huge need for built-in lineman's loops, though they are nice to have. If I absolutely had to minimize my gear, I'd go for them, but I don't.
There used to be a lot of time and energy spent on forums and youtube showing how to install your own. Don't know if that's still a thing.
It's nice to see at least a couple of off-the-shelf options now though, because back in the day you were SOL for that as the move to rock harnesses began.