^^^ Earl's info (first put forth by Dick, IIRC?) is the primary reason I see no value in pursuing this further (a.k.a., let sleeping dogs lie).
Though the letter of the rules is not clear and can be reasonable interpreted both ways, what Earl posits goes a long way toward inferences of the intent of the rule.
And, in fact, were I to pursue a fuel cell in my own cars, as long as I'm happy with the design and placement I'd have no personal issues with using a non-FIA cell (such as Summit's $250 versions). - GA