That's a cool idea! We have several Pi setups which all are powered via 3A capable wall jack to microUSB connectors and use this USB HUB cable
to connect keyboard and mouse. We also attached to all those Pi systems; USB serial adapters, and have always found that we've had to plug the adapters directly into one of the Pi USB ports, not through the cable otherwise it acted flaky. I'm guessing that this HUB here would solve that problem completely. We did try a HUB which has it's own power, and that worked. But this HUB takes that idea one step further.