If you mean you want to power up or test the boards functions without assembling them using the interposer, I'd say no; without a specially-made adapter like the one you're talking about, I don't see how to make enough connections to get the boards working. The two boards are connected via that spacer around the outside edge, and there must be a hundred contact points along the edges of the board, and you'd have to run enough jumper wires between the two boards to enable the functions you want. That means tiny solder spots on each end, and a wire between them. If you take a look at the Qian Li device you're talking about, you'll see there are a lot of spring pins all around the edge; those are the connections you'd have to make.
Frankly, I am skeptical it would be doable, and the consequences of getting even one of those connections wrong could be catastrophic. If you really need to test with the boards separated, I'd strongly suggest getting one of those devices.
Alisha, (@flannelist), do you have any ideas here?
       
      
               
                     
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