@PGRM
I use the iConnectivity MioXM as a MIDI patchbay. It has USB host capabilities.
https://www.iconnectivity.com/mioxm
I am currently trying to control my GAS over the Retrokits RK-006 as a portable USB host and splitter.
I have also used this simple 1-in 1-out USB Midi host in the past.