Thanks John,
The route I went with (albeit clunky):
1) Add extra fields to the checkout process (custom meta stored to order post id)
2) Setup ACF fields and add them to the user (i’m using a role as a rule)
3) Add a function that checks when we hit the Woo Order thank you page
4) Use get_post_meta( $order_id, 'custom_field', $single = true); to get the field added at the checkout
5) Use update_user_meta( $user_id, 'custom_field', $company_name ); to move the info to the user
Whilst it’s not ideal it does achieve what I need. It also means I’ve a hard copy (so to speak) of the additional data submitted by the customer as it’s part of the order
