Help with Ultimatum

Hello, I never got too deep into POE, but I was enjoying this league and wanted to try some late-game farming starts I saw. I was curious about how ultimatum works late in the game, especially with a friend.

As it stands right now, juicing a map to get all the inscribed ultimatums seems to cost around a div; however, every time I go 10 rounds, it doesn't seem like I'm making that currency back at all. I saw all around the internet that running one with a friend will essentially double the ultimatums. When we ran a map, only one person got the inscribed ultimatums while the other got normal rewards. The most recent video I saw on how that works was 3.24. I was hoping for some answers since I can't seem to find any online.