Each time on a fresh install. That's why it seemed odd that it was saying a duplicate key. Unless WHMCS is really wacky.
I'll see if I can find the time to give it a whirl, just was hoping for something sadly a bit more easier and less time consuming, just been a busy start to a new year after a rough 2016, trying to dive into 2017 with something better - at this point even considering blesta as a new front for new sign-ups and slowly migrated legacy accounts over if I can write a tool to import a single account properly, just work with customers on a slow migration throughout the year to finally phase out WHMCS by mid-year, we shall see how it goes.