I had disabled the dark model with 5.4.9.4 due to the number of deepstack errors that I was seeing. I've re-enabled the dark model with 5.4.9.5 and it seems to be working better at first blush. Only one deepstack error so far on the camera that was constantly generating them. I'll have to keep an eye on it and see how it goes.
Still wondering what the Deepstack codes mean. I've seen mostly 100's, with a few 170's, and I think -1 means Deepstack isn't running.
Also noted that static/occupied is still not working consistently.
Update: I ended up turning off custom models again, it was causing Deepstack errors on other cameras and failing to detect properly.