I did actually buy exactly those for the same reason you described. I have, however, not utilised them yet to get signals from one case to another (I’m still lacking a power supply for one of the cases so far) so I can’t comment on any potential issues involved. It should work in theory though…
But you might want to bear in mind that to be able to connect two different cases with these modules would require a little bit of custom work for finding a solution for connecting both ends from one case to another. I’m planning on incorporating a shrouded header into the side of each respective case wired to the respective module. This way I can just plug the ribbon cable into the outer side of each case and don’t have to worry about more precarious (albeit possible) solutions for connecting both modules.
These specific modules seem to be mainly for extending the inputs/outputs of ADDAC213A within the same case of for individual use in one single case. Although, that doesn’t mean one couldn’t come up with other uses as well;)