I would like to re-submit the following points.
ICMP implementation: The fact that Spark doesn’t answer to “PING” is inconvenient, especially when trying to verify that Spark is still alive (typical when CFOD, crash occur without notices or with DHCP address change)
Permanent IP configuration: This is actually an application reliability problem, typically when DHCP server is managed by an ISP. This means that the IP address may change after reboot or at DHCP leasing time expiration, making the application unreachable locally, across firewall or with DNS and port forwarding.
As far as I could retrieve topics about theses subjects it is unclear for me if these are part of future improvements.