Apologies for the late reply. The aggregation methods we refer to are those listed in the CDP-WWF Temperature Rating method, on p 24, so essentially what you are referring to in your post, apart for option d in your post which should be EVIC (Enterprise value + cash) and option a which should be weighted average temperature score. You have also missed Total emissions weighted temperature score, making it 7 different aggregation methods.
So, you don’t have to use the tool for this calculation, but need to follow one of the 7 aggregation methods and the temperature rating method.
Our preferred aggregation methods are the methods listed in the method but in reverse order, i.e. we prefer ROTS over AOTS over ECOTS (EVIC), etc… and the least preferred method is WATS, in the eyes of SBTi.