Are you serious with this minimalist response?
As you may not know yet, this reboot is caused by other USB devices, OTG, headset, earphone from light standby.
The multiplication of reboots causes more serious problems and requires a restart with the volume +- keys.
In clear terms, this phone is no longer usable and your answer is to wait for a new Firmware, around April or so.
You do not offer any solution to roll back to the previous firmware?.
Have you blocked firmware distribution?
Have you checked that it will not be the same case for the normal ROG 5 (Non S), according to my experience as a developer there is no reason that the problem is not identical, the platform being almost identical.
Have you put more important means to distribute a new Firmware in the days that follow.
Must I remind you this is your premium ROG series phone, your showcase of mobile gaming.