I don't have any experience with the Whiskey forks. I do have a few thoughts. If concerned about the look with all the clearance around the tire that you might get with the CROSS fork, Whiskey also offer NO.9 Carbon Thru Axle ROAD Fork that is designed for a 28mm tire on a 23mm rim. Either way, both of the forks are spec'd with a maximum disc size of 185mm. Generally tandems use 203mm discs.
In the end, I would follow the lead of Calfee. They know what they are doing.