Support has access to this info, I suspect. Yet, it would be helpful, during development, to see "what did I just do?" in relation to an app or driver just added. Before and after, in a sense.
My "vote" is for access to some means to detect "something is misbehaving" - without regard as to how that info is shared.. driver, extended status URL, etc. I already know that /reboot does that, could there be a /diagdata ?
"I suspect". No, not without inordinately digging into things, which we ordinarily would not do. It sounds like you are talking about how to debug your code. These sort of diagnostics aren't the means to do that, and generally won't help that.
I guess it's more a "do I need to debug my code?" issue. I'd like a clue about "Do I have a memory leak?" or any of the hundred other instability potentials. With the data one can gather a baseline and then run some tests and get trend data.
here are a few i had in mind ... @csteele has already mentioned some of the same:
hub crawling ... reboot hub.
hub misbehaving check stats.
driver misbehaving check stat.
app misbehaving check stats.
hub is a device thats hosts child devices and apps ... treat like a device and expose device details.
cooler than the other guys.
its not about debugging the platform. its about debugging the effects of a driver or app on the platform. this information would be an enormous help for many developers who are writing code to run on this platform.
I use my Asus Router's built-in OpenVPN server capability to allow me to have full, secure, remote access to my home network. This allows me to connect my OpenVPN client on my phone when away from home and make changes, reboot (rarely), and even kick off a firmware update on my Hubitat Elevation hub.
FWIW, we don't do any of this in developing the apps and drivers for this platform. Finding it hard to imagine that stats could help if a hub/driver/app is "misbehaving". If you know it's misbehaving, why not debug it? Sorry, just not believing the "enormous help" line at all, and that comes from having a lot of experience developing apps and drivers on and for Hubitat Elevation.
On top of that, we'd rather put our resources to work improving the platform for home automation users than putting effort into making it a "cooler developer's platform". We are happy that you and others can develop apps and drivers on the platform -- we do it every day ourselves. So we have a pretty good handle on what it takes. This is my polite and hopefully logical explanation of why this isn't going to happen.
from experience ... teams that build the platform generally have different level of access from users that build apps that run on those platforms. often leads to differing perspectives between platform teams and app dev teams.
I'm gathering by my searching that hub as a device probably won't every happen. What I've been looking for is a way to pull data of attached devices, like temperature sensors, out via SNMP to display in PRTG for graphing and visualisation.