Here in Southern Minnesota, elm has been widely available for 30 years because of Dutch Elm disease. First thing I do when looking at an elm is get a chunk and try splitting it. Then I decide how much effort to put into it.
Red elm(Slippery or Rock Elm) is primo firewood. It can sit in the woods for years without much rot. The bark falls off easily, so it is really clean wood. It usually splits OK until the pieces get 20-25” across. Then you need wedges or a power splitter. Burns nice, hot, with little ash.
White elm is OK. Splits hard by hand, but pretty good with a hydraulic splitter. Smaller branches are nice wood that usually is dry enough to use right away if need be. The trunks are really hard to split. There are lots of old yard trees with trunks 3 or 4 feet across that are not worth a lot.
Chinese elm seems like crappy white elm. I’ve burnt it, but wouldn’t go out of my way to get any unless I was desperate.
"Elm burns like the churchyard mold,
even the very flames are cold."