Suitcase challenge was held in 2021 and the top 3 were 590, 560 and 460 pounds. In 95th place the entry was 95 pounds and 50th place was 252.5 pounds. I can certainly manage 100 pounds each hand and could not manage over 150 pounds, but I am not sure where the sweet spot is.
UPDATE: 2/14/2022 1800 (about an hour later) - 95# resulted in an epic fail at about 20 seconds. 75# was fine and 80# felt near max effort. That would be a 160# total placing me at roughly 85 out of 95 in the 2021 leaderboard.
Balancing the bars was harder than I expected and a hook grip without tape really bit into my thumb.