Eab_EventsHub::process_rsvps() not picking up $_POST['user_id']

Literally what the topic says;

Eab_EventsHub::process_rsvps() not picking up $_POST['user_id'], it's hardcoded to $current_user->ID. Since we're posting in a user_id, could we please use that one for the rsvp please?

We've hacked it locally but think it should probably use the POST value 'for real'

Many thanks.