Good conventions is what I'm wanting to know - but I think I am also a bit ignorant on what constitutes an IOT device.
Where I have made the mistake is that my project isn't really an Internet device but merely a wireless switch that happens to use TCP/IP to access sensors all within a private network. So not really an INTERNET device. Though it could be deployed across the Internet than it would make sense to use a public MQTt server to handle the data. Which in MY application is not required but perhaps I should rethink my implementation.