Since SQ-Drive appears to have massive Problems with several USB Storage devices (not only thumb drives by far) and it is practically impossible to predict which USB Storage device to order that will work with it especially but not only when it comes to Multitrack Recording, anyone who really needs that functionality should at least consider using some Notebook or small Computer Device (Raspi?) for Recording and Playback via the USB A Port as “Plan B”.
That way it works much more flawless and reliable and allows to do recording and playback simultaneously even to USB Storage devices not working on USB Port B that are fast enough to handle the data.