My answers, questions :
Example: I have 5 motion detectors. If am asking them separately, I need 5 questions to each. I can not ask them in one batch - server HE is going down (necessary 3 seconds delay) and I must wait for answer. It will lead that for each sensor I am waiting at least 15 seconds.
Websocket - it is solution. However how to implement that on HE? According discussion websocket is existing but not supported. https://community.hubitat.com/t/suggestions-for-output-on-websockets/12369
Maker API is sending answer state of device after sending of command not only Succes 200.
Wall switch tested 1 meter from servers and of course only one Z-wave network active etc.