I had been under the belief that this game used IGT for the primary timing however the second place time which is slower RTA has a faster IGT. Is RTA the primary timing method or is IGT just not set as the default in settings for some reason?

IGT is the time that taken for ranking, I've been messing with the mod settings to see if I can get IGT set as primary or RTA hidden.

You should be able to set IGT as the first time with real time as the second