Unfortunately Microsoft puts them behind a developer account and NDA requirement. The less specific docs can be viewed here but they tend to only make vague references to the restrictions (mentioning things like API service needing to be discussed and set up with your point of contact, etc.): https://learn.microsoft.com/en-us/gaming/gdk/_content/gc/live/features/multiplayer/live-multiplayer-intro
The problem with cross console on private servers tends to come from the rules set forth by the company. Microsoft has a lot of restrictions on how cross platform multi-player can be implemented, and since the servers are being hosted by the players and not the company they most likely aren’t able to meet the requirements.
I find people online tend to have a lot more passion for arguing than I do so I often rethink posting any responses I come up with.
With the food timers, as far as I can tell only the top unit expires, so you can jam 100 baked berries in your feed bag and not have to worry about managing hunger for a few hours