So didn't know there was an internal USB flash drive or didn't see it as an option when loading the ESXi installer.
I will get the ESXi 6.5 u2 but how to I choose or make the internal USB drive as an option to choose instead of the 4 SATA drives that I have? ( I recall that was the only options available to me to choose from).
In the event if there is a failure on the USB , I can easily re-install ESXi again and still use the Datastore drives (assuming those are working just fine).