@dc42 - So sorry for starting this thread then going silent. I thought I had it set to email me when there were replies (newbie error).
I'm running a Duet2 clone board and have the RR3.3 firmware running. I'm not near the machine now so I can't look for a more detailed version number, but I downloaded mine at the end of June.
My homez.g is attached and you'll see I don't have an M292 in it, just the M291. homez.g Apologies fr the extraneous comment lines at the end. They are a leftover from the file when I inherited it.
And I'm running standalone. And I've tried this with web control and also PanelDue. I get the error messages on both.