I kinda of reject the premise of the question as I don't think the entire thing is fair way of handling disputes! As far as I'm concerned both RoRA S5 and Byelaw 18 should be repealed ASAP. For serious matters the Fraud Act would seem to be a useful weapon in the arsenal (such as
this guy who forged his season ticket and was, as it happens, done for fraud) but otherwise I'm not sure that there needs to be a specific
criminal sanction for fare evasion.
Personally I would support adapting the Penalty Fare regime to cover the majority of situations. Let's hike it up to £100 reduced by say 50% if paid or an appeal lodged (regardless of the eventually outcome as appealing would just pause the clock) within 14 days along with whatever the appropriate single fare would have been. Fail to pay within 28 days or come to a payment arrangement (or later break a payment arrangement) and they can take you to county court for the whole amount outstanding. And whilst it's a much less severe sanction (as it should be) a County Court Judgement still comes with all sorts sticks (credit rating aside) when it comes to enforcement if you still don't pay including bailiffs, attachment of earnings or charging orders.
It seems to me that fare evasion is, quite logically, a civil matter and it's time that the legislative framework was changed accordingly. Not that I have any expectation of such a thing happening.