So I just found out that this is a thing.
If you use the M556 Axis compensation with the RRP firmware supplied with the Ormerod 2 it throws off the position of the other axis.
Anyone know if there is a fix yet? I know I should just flash DC42's firmware but I'm not quite ready to do that yet as I've only just built the thing.
Disapointing that there is no mention of this issue in the build documentation, took me a while to figure out just what was going on!