I spoke too soon. Older profiles are properly useable in LR but I can't make a profile for my X2D. I don't think that the old x-rite export preset within LR works anymore. But I did make a profile using the Color Checker app. It was put in my username/Applciation Support/Adobe/Camera Raw/Camera Profiles folder. Not recognised by LR and not available to it. And I haven't found a way of importing it via LR since it is not possible to access the username/Library folder without using option + go from the Finder menu.
Looking at where the other, recognised profiles were stored, I found them and copied the X2D profile into the same folder. I then tried to import it and was given the message that it couldn't be imported since it had already been imported.
This is getting a bit frustrating. Time I guess to get onto Adobe Support.