I have never found a good way to assign persistent names to USB-to-serial adapters. After all ideally the name should identify the USB port where the device is plugged, not the order of plugging.
Currently I do it with udev rules mapping physical device paths (which includes PCI and USB)to names but UDEV constantly complains that PHYSDEVPATH is deprecated. I have no idea what the "preferred" solution is.
In Windows all devices by default have persistent physical location ids. It is even possible to associate completely different drivers with the same devices plugged into different PCI slots. We still have some ways to go before reaching equality even with Windows 2000's device model.