As you say, very little exists in them and even as late as 3 Feb 2020 , reclassification /listing/recognition is still ongoing. However best guess appears to be 35cm.
I don't think you would go too far wrong with husbandry similar to the common tyre track eel (mastacembelus armatus). Main thing to watch obviously is the fact you have baby escape artists.
I heard they get 14 inches
Yeah lots of t rex tape lol everything is completely sealed I'm going to keep this updated. Some of their natral habitat is is shrinking one area by 90%. I will post what information I find on them.