MS Project custom fields on Dataverse

Hi Paul_Mather,

You seem to be quite well informed, so I hope you don't mind me asking - I've gone through a number of answers/articles related to this topic but haven't quite seen the answer I'm looking for.. the custom columns are not stored in the Dataverse, but where are they stored? no one seems to have provided this information, and the data would need to be stored somewhere? do you or any other knowledgeable people in the forums know how/where the data is stored?  

At this point I don't even care if it's not in a location I can pull from, not knowing where its stored is eating me up.

Thanks in advance for any assistance and help across these forums! 
Tenielle