I see the problem here: "drag" riders on endurances rides "entering" for
free. I think the operative word here is "entering". If you are drag
riding, you really can't be competing. Your responsibilities are such
that it is highly possible (if not probable) that you will not be able to
complete the mileage in the allotted time. I have always used drag
riding as conditioning rides.
In the NATRC rides I have 'dragged', you did not pay anything, but you
also did not get
completion awards, and did not expect them, either. You were, however,
considered part of ride management and were given all the applicable
'perqs', such as food, etc.