Update - It's fixed!

Papiosaur got in touch and it turns out the controller has a PC Mode and an XBox mode and when I switch to PC Mode it appears as a hid.class device and is recognised by EUAE.

So pleased to now have a controller I can use with things like SWOS Total Pack.

Also a big thanks for Papiosaur and his MorphOS Store, as the work he does in checking compatibility really helps take the leg work out of buying and trying stuff out for yourself. Delivery was really quick to the UK as well.