>I saw that setting for playing DVDs automatically, but I was wondering if any more control were possible.
well at least i think so. you can open the dvd tray: goto the API Browser i mentioned before and type in search "system.ejectopticaldrive" and in the params field simply put [].
>If I understand you correctly, Kodi would need to provide some JSON/RPC functions for controlling the optical drive, and then Chorus would need
>to be modified to have a button or menu pick to actually call them.
>Is that right? Does Chorus drive Kodi entirely by making calls through this API?
Yes that is right afaik. i case there would be an api call which works for you, you also could make a very simple page yourself which does only that. or you could fire it with a simple command from the shell. best solution would be to implement it to chorus yourself and commit it to the project. give the project is still maintained.
>I notice a number of other problems with Chorus (e.g., the music player) and I'm wondering if Kodi v18 introduced changes
>to the JSON/RPC API which have broken Chorus.
i don't know, i don't actually use chorus... sorry. but yes, there is a new API but i did not read into changes. Here you can find information about that:
https://kodi.wiki/view/JSON-RPC_API
>I tried looking at the GitHub repo but it seems that Chorus 2 hasn't been updated in a while.
>I also couldn't find much documentation on it (e.g., is the web API for Chorus documented anywhere??). This has me a bit worried, tbh.
i don't know about that either sorry.