From the rules, as written... (
https://www.ironbutt.com/themerides/ssseries/index.html)
"WARNING: If your motorcycle is equipped with a large fuel-tank, please note that you must stop at least once every 350 miles for gas (this is purely for documentation for your ride). Although we know it is possible to ride greater distances non-stop, we will not accept a claim of this type."
So, technically he need only STOP for fuel. So, if he has pre-purchased and stored, stops and refuels and can document the stop (SPOT, photo etc.) then he is technically within the confines of the rules. A time, date & location stamped photo with GPS coordinates of his 'fuel store' could be considered 'evidence' - collaborated with SPOTWALLA.
In fact, if they/he leave a receipt with the fuel store - he meets the requirements 'as stated':
A log entry must be made at each gas stop (sample attached). A log entry includes the following information; DATE, TIME, TIME ZONE, LOCATION (i.e. Moline, IL) and ODOMETER reading. A receipt must accompany each log entry (please note, that the receipts from these gas stops, where possible should include a date stamp -
we do NOT care about time stamps on these receipts, do not waste time worrying about time stamps, the only time stamps that are critical are the start and finish receipts!). Add an explanation (pretty much already documented here in the public domain) as to the how and why.