Was the T_3.6 picked for the second USB HOST port? So far most effort on that was for host usage - not sure about support for being a client to the second computer.
If you put two T_LC's ( or 3.2, 3.5, 3.6 ) side by side with a Serial connection each could talk to one computer and share that data over the connection ( Serial or SPI with SPI_MSTransfer or other ).
Two T_LC's would cost less - but not have the same potential for Serial throughput that T_3.2 and above would if that is critical, though SPI might improve that on T_LC.
Two T_3.2's with Serial1 and Serial2 used in parallel might offer 6-8 Mbps throughput, though they might do even better with the SPI_MSTransfer which comes with error check and retry.