You may want to see what happens with the Matter protocol, which is nearing final. As I understnd it, it is essentially the latest version of zigbee. Many major players in the industry will be supporting it.
Is there a way to eliminate the requirement to login to the local web interface of the ISY994i (v4.7.3)? This would be for LAN access only. We don't allow any external access (no port forwarding, etc).