I had 4 replies on 4 different threads... My opinion((you can have yours and you dont have to criticise mine):
1) has to be someone currently in Andromeda. so it will not be not TIM, not the citadel council, not the shadow broker, not anyone in the Milky Way during ME2/ME3.
2) Not SAM he was clearly still being manufactured,
3) He's done well in EOS. (as per the note in the kett base where the moshae is held.)
I am hoping it's someone new. His MO is like Reyes, but scales are very different. I spoke with a lady called Kim Connor, the EOS supply officer I am still trying to go back every now and then to speak with her, this latest conversation she mentioned that she was once from a wealthy family in the milky way... Her last sentence is "Precious things makes you a target. And drastic steps are sometimes needed to protect them. No more for now." I dont think she is the Benefactor, seem too low key and too far down the food chain, but perhaps related to the benefactor? An agent? Will go back again to see if there's a conclusion to her conversation.