Having trouble understanding blue mmwave VZM32-SN "stay" settings/parameters

I’ve read all the documents and all of the message board topics I could find but am confused about:

  1. How does “detection area” differ from “stay area”? If I’m trying to use this in a room where people are usually sitting, is it expected I will configure both detection area and stay area, potentially for the exact same area? Or are they mutually exclusive?

  2. When I try to set stay areas, it frequently does not keep the numbers I set and moves it around, unlike the detection area. Is this potentially a bug or is something else happened?

  3. What is MmWaveStayLife? It says it is “the delay time of the stay area” but I’m not sure what that means? Is it the delay until the “stay” is detected? The length of time something stays detected? Something else?

  4. for “depth”, at least in zigbee2mqtt it reports the minimum value is 0 (0 to 600). However, I see targets reported as far back as -100, and I appear to be able to set the areas to a depth as far back as -100. Is that OK to do? Is it a mistake with zigbee2mqtt configuration, or not recommended, or something else?

Thanks!