Are you adding support for the extra XP that flex fares are earning? Also, I know this is still a test, but what about no XP for light fare?
My suggestion, if you're building this, would be that you add the ability on your back-end to configure fare brands, and associate how much XP each brand type gives. Perhaps a good way would be to have a standard XP table, and allow defining per-fare brand increases or decreases. This will let you deal with any future fare related XP exceptions that appear (which I strongly suspect are coming).