24 HR MTB

Hi uys not sure if any one can help but i am training for a 24 hr mtb race and trying to use the new AI forecast selecting event and entering the details as best as possible to outline the race but there is an option for 12hr which i have selected at the moment but no 24 hr option obviously this is a small market but was wondering if that is the best option to train to or is there some other tricks of the Xert trade to better leverage the system that i haven’t yet mastered ( am stillnew to the Xet way of thinking coming from other training methods) any help would be much appreciated.